• 제목/요약/키워드: 지역

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Seasonal Variations of Particle Fluxes in the Northeastern Pacific (북동태평양 심해에서 관측된 퇴적물 입자 플럭스의 계절적 변동)

  • Kim, Hyung-Jeek;Kim, Dong-Seon;Hyeong, Ki-Seong;Kim, Kyeong-Hong;Son, Ju-Won;Hwang, Sang-Chu;Chi, Sang-Bum;Kim, Ki-Hyun;Khim, Boo-Keun
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • 제13권3호
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    • pp.200-209
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    • 2008
  • Particle fluxes were measured with a time-series sediment trap from July 2003 to June 2005 at the St. KOMO(KOMO; Korea Deep-Sea Environmental Study Long-Term Monitoring Station, $10^{\circ}30'N,\;131^{\circ}20'W$) in the northeastern Pacific. Total mass fluxes at a depth of 4,960 m showed distinct seasonal variations with high values in the winter(December-February) and spring(March-May) and low values in the summer(June-August) and fall(September-November). Biogenic origin fluxes also displayed distinct seasonal variations similar to total mass fluxes. Particularly, calcium carbonate fluxes in winter and spring were more than two times greater than those in summer and fall. The prominent seasonal variations of total mass and biogenic fluxes were closely related with the seasonal changes of primary production in the surface waters; in winter and spring, primary production increased due to the enhanced supply of nutrients below the surface mixed layer by strong wind and less stratification, whereas it decreased as a result of the less supply of nutrient by reduced wind speed and strong stratification in summer and fall. The seasonal variations of total mass and biogenic fluxes in this study were higher than the differences of total mass and biogenic fluxes caused by the environmental changes such as El $Ni\tilde{n}o$ and La $Ni\tilde{n}a$ events in the previous studies. In order to understand the effects of El $Ni\tilde{n}o$ and La $Ni\tilde{n}a$ on the particle flux, therefore, the seasonal variation of particle flux in the northeastern equatorial Pacific needs to be well defined.

Development of Marine Ecotoxicological Standard Methods for Ulva Sporulation Test (파래의 포자형성률을 이용한 해양생태독성시험 방법에 관한 연구)

  • Han, Tae-Jun;Han, Young-Seok;Park, Gyung-Soo;Lee, Seung-Min
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • 제13권2호
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    • pp.121-128
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    • 2008
  • As an aquatic ecotoxicity test method, a bioassay using the inhibition of sporualtion of the green macroalga, Ulva pertusa, has been developed. Optimal test conditions determined for photon irradiance, pH, salinity and temperature were $100\;{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, $7{\sim}9$, $25{\sim}35\;psu$ and $15{\sim}20^{\circ}C$, respectively. The validity of the test endpoint was evaluated by assessing the toxicity of four metals (Cd, Cu, Pb, Zn) and elutriates of sewage or waste sludge collected from 9 different locations. When the metals were assayed, the $EC_{50}$ values indicated the following toxicity rankings: Cu ($0.062\;mg{\cdot}L^{-1}$) > Cd ($0.208\;mg{\cdot}L^{-1}$) > Pb ($0.718\;mg{\cdot}L^{-1}$) > Zn ($0.776\;mg{\cdot}L^{-1}$). When compared with other commonly used bioassays of metal pollution listed on US ECOTOX database, the sporualtion test proved to be the most sensitive. Ulva sporulation was significantly inhibited in all elutriates with the greatest and least effects observed in elutriates of sludge from industrial waste ($EC_{50}=6.78%$) and filtration bed ($EC_{50}=15.0%$), respectively. The results of the Spearman rank correlation analysis for $EC_{50}$ data versus the concentrations of toxicants in the sludge presented a significant correlation between toxicity and four heavy metals(Cd, Cu, Pb, Zn). The method described here is sensitive to toxicants, simple to use, easy to interpret and economical. It is also easy to procure samples and maintain cultures. The present method would therefore probably make a useful assessment of aquatic toxicity of a wide range of toxicants. In addition, the genus Ulva has a wide geographical distribution and species have similar reproductive processes, so the test method would have a potential application worldwide.

Sources Identification of Anthropogenic Pb in Ulleung Basin Sediments using Stable Pb Isotope Ratios, East/Japan Sea (동해 울릉분지 시추 퇴적물에서 안정 Pb 동위원소를 이용한 Pb의 기원 추정)

  • Choi, Man-Sik;Uoo, Jun-Sik;Kim, Dong-Seon
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • 제12권4호
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    • pp.315-327
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    • 2007
  • This study investigated temporal and spatial variation of Pb and stable Pb isotopes accumulated in Ulleung Basin core sediments (4) using MC ICP/MS in order to identify the sources of anthropogenic Pb in the East/Japan Sea. Leached (1M HCl) Pb concentration and isotope ratios ($^{207}Pb/^{206}Pb\;and\;^{208}Pb/^{206}Pb$) were nearly constant during 300 yrs past than 1930, but increased up to twice in concentration and as much as 3.41% (1.70%) after 2000. On the other hand, residual Pb concentrations were nearly constant for past 400 yrs. The accumulation rates of anthropogenic Pb in the basin area were in the range of $3.1-3.5mg/m^2/yr$, which were similar levels to total atmospheric Pb deposition fluxes from 1990s to the present. In the slope area, more increase of anthropogenic Pb accumulation than the levels expected from mass accumulation rate could be found after the middle of 1990s. From the detailed evaluation for the temporal and spatial variation of accumulation rate and isotope ratios of anthropogenic Pb, we proposed probable sources and pathways of anthropogenic Pb. Pb emmision by coal burning from the China and Korea initiated the accumulation of anthropogenic Pb in the sediments of East/Japan Sea from 1930s. The accumulation of Pb increased by the addition of anti-nocking agents from both countries untill the beginning of 1990s, but from the middle of 1990s to the present, the phase-out of gasoline additives and the rapid increase of coal burning from the China maintained the atmospheric Pb levels in the Ulleung basin nearly similar to before. However, the local sources within this basin might take an important role in the rapid increase of anthropogenic Pb accumulation in slope areas from the middle of 1990s.

Change of Blooming Pattern and Population Dynamics of Phytoplankton in Masan Bay, Korea (마산만 식물플랑크톤의 대발생 양상의 변화와 군집 동태)

  • Lee, Ju-Yun;Han, Myung-Soo
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • 제12권3호
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    • pp.147-158
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    • 2007
  • To clarify the bloom pattern and species succession in phytoplankton community, the population dynamics with the determination of physico-chemical factors have been studies in Masan Bay, the south sea of Korea, for the periods November 2003-October 2004. Concentration of $NH_4-N$ was always higher than that of $NO_3-N$, which was similar level as compared to other costal areas. $PO_4-P$ concentration was lower than those in other coastal areas but similar to oligotrophic environments. Thus, phosphate seems the limiting nutrient rather than nitrogen. $SiO_2-Si$ concentration was also low as compared to other costal areas. Si:P ratio was low from autumn to winter, suggesting silicate and/or phosphate limitation during this period. The cell density of phytoplankton was high in winter 2003 and early autumn 2004. The carbon biomass was high in winter 2003 and summer 2004. And chlorophyll-a concentration was high in late autumn 2003 and summer 2004. Among 78 species of phytoplankton found in the bay during the investigated period, dominant species were two diatoms of Cylindrotheca closterium, Skeletonema costatum, and three dinoflagellates of Heterocapsa triquetra, Prorocentrum minimum, P. triestinum, and one raphidophyte of Heterosigma akashiwo. P. minimum dominated from late autumn to winter, but it was replaced by H. triquetra in late winter. P. triestinum dominated from late spring to early summer. Simultaneously, H. akashiwo cell density steadily increased, and it became dominant with C. closterium in late summer. With decreasing of H. akashiwo and C. closterium, S. costatum became the most dominant species in autumn. The canonical analyses showed that total phytoplankton cell density related to diatom cell density and it was affected by temperature, and concentrations of $NO_3-N\;and\;PO_4-P$. The carbon bio-mass and $chlorophyll-{\alpha}$ concentration related to diatom- and dinoflagellate cell densities and these were affected by flagellate cell density, salinity, and concentrations of $SiO_2-Si\;and\;PO_4-P$. Last six years monitoring data in Masan city obtained from Korean Meteorological Agency indicates gradual increase in air temperature. And the precipitation decreased especially in spring season. The winter bloom found in 2003 may be caused by the increase in the temperature and this bloom subsequently induced the nutrients depletion, which continued until next spring probably due to no precipitation. Therefore, the spring bloom, which had been usually observed in the bay, might disappear in 2004.

A Flora of Vascular Plants in Boraebong (보래봉 일대의 관속식물상)

  • Ji Eun Kim;Young-Soo Kim;Jung Sim Lee;Ju Eun Jang;Hyeon Jin Jeong;Aleksey L. Kim;Sang-Kuk Han;Hee-Young Gil
    • Korean Journal of Plant Resources
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    • 제37권1호
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    • pp.35-61
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    • 2024
  • Floristic study can help to understand the current status of species diversity, evaluate and predict distribution changes of plants based on the specimens, and record the climate environment and biodiversity of the Korean Peninsula. Boraebong is an area that has plant resources of conservation value, but there is concern about artificial interference through trail and forest road. Therefore, this study aims to report the vascular plants of Boraebong based on voucher specimens and photos and to use them as baseline data to conserve biodiversity of Boraebong. Also, it will be useful to prevent additional influx of invasive species through comparison with previous studies. The investigation was carried out 11 times from April to September in 2022 and confirmed a total of 455 taxa including 87 families, 269 genera, 401 species, 13 subspecies, 35 varieties, 6 forms. In addition, we confirmed the 4 taxa of red list plants (EN 2 taxa, NT 2 taxa), 18 taxa of Korean endemic plants, and 102 taxa of floristic target species (V degree 1 taxon, IV degree 16 taxa, III degree 31 taxa, II degree 31 taxa, I degree 23 taxa). Furthermore, alien plants 17 taxa, invasive species 2 taxa, useful plants 439 taxa were confirmed in Boraebong. As the results of comparison with previous studies, 98 total taxa including 38 families, 76 genera, 86 species, 1 subspecies, 8 varieties, 3 forms were newly identified in this study.

A Study on the Korean Shamanistic Myth "Samgong Bonpoori" from the Perspective of Analytical Psychology (무가 '삼공본풀이'에 대한 분석심리학적 고찰)

  • Myung-sook Hwang
    • Sim-seong Yeon-gu
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    • 제30권2호
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    • pp.145-186
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    • 2015
  • This thesis discusses and analyzes Jeju island's shamanistic myth "Samgong Bonpoori" from the perspective of analytical psychology. Similar to the "I live on my fortune"-type folktales discovered in the Korean mainland, "Samgong Bonpoori" is such a widespread myth that similar folktales are found not only in East Asian regions, including Korea, Japan, and China, but also in Ireland. The essence of the story is as follows; One day, a father asked his three daughters whose fortune they lived on. The first two daughters claimed that they owe their lives to their parents. However, the youngest daughter, Gameunjang-agi, replied, against his expectation, that "I live on my own fortune," and showed her fortune and virtue were physically embodied in the line drawn from her genitals to navel. Her answer enrages his father so fiercely that she was expelled and forced to embark on a journey with no one but a black cow carrying food to accompany her. In retaliation for telling lies against her, Gameunjang-agi transformed her two sisters into a centipede and a mushroom, while her parents were turned into beggars afflicted with blindness. Afterward, Gameunjang-agi wandered around the country and eventually found love with a Chinese yam digger. Not long after, they got married, and as a couple, they stumbled upon roots of gold in fields, which brought them an incredible amount of wealth. After this miracle has happened, Gameunjang-agi began to wonder about the status of her parents and decided to organize a party for all the beggars and the blinds in the country. She eventually found her parents and got a chance to reconcile with her sisters. The story ends with her parents regaining their eyesight and Gameunjang-agi reestablishing herself as the "Goddess of Providence." "Samgong Bonpoori" is a myth about a God. A God is ontologically a supremely perfect being; however, in this thesis, it will be discussed as a part of a folktale. Gameunjang-agi can be seen as the anima archetype of the father, which reveals the process of a paternal consciousness being transformed over time. At first, her parents deny Gameunjang-agi. However, after years of suffering from blindness, they regain their eyesight and finally recognize their daughter. This signifies that Gameunjang-agi is a being that has come into the world for a certain "purpose." Gameunjang-agi embodies the creative function of "femininity" that can renew the existing collective consciousness embedded in the patriarchal system. Such recognition of femininity matters to men to a great degree as well as to women. Without knowing their true nature (femininity), the two sisters submit themselves to their parents and conventional values. Not until they suffer from being transformed and captured into small and insignificant beings, a centipede and a mushroom, which symbolize their shadow, they fail to develop their self-awareness. Meanwhile, by reconciling with her parents and sisters--playing a significant role in reuniting the family--Gameunjang-agi turns out to be a figure that can reveal what it truly means to have self-awareness and achieve Self-realization. In conclusion, this story illustrates that recognition of femininity matters to men to a great degree as well as to women, and women's Self-realization plays a critical role in revitalizing the collective consciousness embedded in the patriarchal system.

A Study on Space Creation and Management Plan according to Characteristics by Type in Each Small-Scale Biotope in Seoul - Base on the Amphibian Habitats - (서울시 소규모 생물서식공간 유형별 특성에 따른 조성 및 관리방안 연구 - 양서류 서식지를 중심으로 -)

  • Park, Ha-Ju;Han, Bong-Ho;Kim, Jong-Yup
    • Journal of the Korean Institute of Landscape Architecture
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    • 제52권2호
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    • pp.110-126
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    • 2024
  • This study conducted a classification of small-scale biological habitats created in Seoul to analyze and synthesize location characteristics, habitat structure, biological habitat functions, and threat factors of representative sites, as well as derive creation and management problems according to the ecological characteristics. The aim was to suggest improvement measures and management items. Data collected through a field survey was used to categorize 39 locations, and 8 representative sites were selected by dividing them into location, water system, and size as classification criteria for typification. Due to the characteristics of each type, the site was created in an area where amphibian movement was disadvantageous due to low or disconnected connectivity with the hinterland forest, and the water supply was unstable in securing a constant flow and maintaining a constant water depth. The habitat structure has a small area, an artificial habitat structure that is unfavorable for amphibians, having the possibility of sediment inflow, and damage to the revetment area. The biological habitat function is a lack of wetland plants and the distribution of naturalized grasses, and threats include the establishment of hiking trails and decks in the surrounding area. Artificial disturbances occur adjacent to facilities. When creating habitats according to the characteristics of each type, it was necessary to review the possibility of an artificial water supply and introduce a water system with a continuous flow in order to connect the hinterland forest for amphibian movement and locate it in a place where water supply is possible. The habitat structure should be as large as possible, or several small-scale habitats should be connected to create a natural waterfront structure. In addition, additional wetland plants should be introduced to provide shelter for amphibians, and facilities such as walking paths should be installed in areas other than migration routes to prevent artificial disturbances. After construction, the management plan is to maintain various water depths for amphibians to inhabit and spawn, stabilize slopes due to sediment inflow, repair damage to revetments, and remove organic matter deposits to secure natural grasses and open water. Artificial management should be minimized. This study proposed improvement measures to improve the function of biological habitats through the analysis of problems with previously applied techniques, and based on this, in the future, small-scale biological habitat spaces suitable for the urban environment can be created for local governments that want to create small-scale biological habitat spaces, including Seoul City. It is significant in that it can provide management plans.

A Comparative Study on Factors Affecting Satisfaction by Travel Purpose for Urban Demand Response Transport Service: Focusing on Sejong Shucle (도심형 수요응답 교통서비스의 통행목적별 만족도 영향요인 비교연구: 세종특별자치시 셔클(Shucle)을 중심으로)

  • Wonchul Kim;Woo Jin Han;Juntae Park
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • 제23권2호
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    • pp.132-141
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    • 2024
  • In this study, the differences in user satisfaction and the variables influencing the satisfaction with demand response transport (DRT) by travel purpose were compared. The purpose of DRT travel was divided into commuting/school and shopping/leisure travel. A survey conducted on 'Shucle' users in Sejong City was used for the analysis and the least absolute shrinkage and selection operator (LASSO) regression analysis was applied to minimize the overfitting problems of the multilinear model. The results of the analysis confirmed the possibility that the introduction of the DRT service could eliminate the blind spot in the existing public transportation, reduce the use of private cars, encourage low-carbon and public transportation revitalization policies, and provide optimal transportation services to people who exhibit intermittent travel behaviors (e.g., elderly people, housewives, etc.). In addition, factors such as the waiting time after calling a DRT, travel time after boarding the DRT, convenience of using the DRT app, punctuality of expected departure/arrival time, and location of pickup and drop-off points were the common factors that positively influenced the satisfaction of users of the DRT services during their commuting/school and shopping/leisure travel. Meanwhile, the method of transfer to other transport modes was found to affect satisfaction only in the case of commuting/school travel, but not in the case of shopping/leisure travel. To activate the DRT service, it is necessary to consider the five influencing factors analyzed above. In addition, the differentiating factors between commuting/school and shopping/leisure travel were also identified. In the case of commuting/school travel, people value time and consider it to be important, so it is necessary to promote the convenience of transfer to other transport modes to reduce the total travel time. Regarding shopping/leisure travel, it is necessary to consider ways to create a facility that allows users to easily and conveniently designate the location of the pickup and drop-off point.

Study on Geological Distribution of Fluorine in Forest Aggregate within Korea (산림골재 내 불소의 지질학적 분포 연구)

  • Yeong-Il Jeong;Kun-Ki Kim;Soon-Oh Kim;Sang-Woo Lee;Jin-Young Lee
    • Economic and Environmental Geology
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    • 제57권2호
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    • pp.233-241
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    • 2024
  • This study was conducted to investigate the geological distribution characteristics of fluorine in rocks, which can be a major resource of forest aggregates in Korea. Samples of forest aggregates were collected from 224 sites in 22 cities and counties for this study. The national background concentration was 344 mg/kg, which was significantly lower than the average fluorine concentration of crustal, which was 625 mg/kg, and slightly higher than the average fluorine concentration of world soil, which was 321 mg/kg. In terms of region and tectonic structure, fluorine concentrations were investigated to be highest in Gyeonggi-do(394 mg/kg) and Gyeonggi massif(396 mg/kg), respectively. The concentration distribution by the origin of the parent rock was in the order of metamorphic rock(362 mg/kg) > sedimentary rock(354 mg/kg) > igneous rock(328 mg/kg), and the concentration distribution by geologic ages was the highest in the Paleozoic at 394 mg/kg. The concentration distribution by rock types was in the order of diorite(515 mg/kg) > gneisses(377 mg/kg) > schists(344 mg/kg) > phyllite(306 mg/kg) > granites(305 mg/kg) > quartz porphyry(298 mg/kg). Consequently, it is speculated that gneisses and schists, Precambrian metamorphic rocks in the Gyeonggi massif that forms the crust of Gyeonggi-do, contain high fluorine concentrations.

Breeding of New Ever-bearing Strawberry 'Miha' with High Hardness (고경도 사계성 딸기 '미하' 육성)

  • Jong Nam Lee;Jong Taek Suh;Su Jeong Kim;Hwang Bae Shon;Ki Deog Kim;Hye Jin Kim;Mi Ja Choi;Yul Ho Kim;Su Young Hong
    • Korean Journal of Plant Resources
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    • 제37권1호
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    • pp.87-92
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    • 2024
  • 'Miha' is a new strawberry (Fragaria x ananassa Duch.) cultivar, which was released by the Highland Agriculture Research Institute in 2019. The 'Miha' cultivar originates from a 2014 cross between 'Monterey' and 'Saebong No. 3', both of which exhibited excellent ever-bearing characteristics, including continuous flowering and large fruits under long-day and high temperature conditions. This new cultivar was initially named 'Saebong No. 12' after examining its characteristics and productivity during summer cultivation between 2015 and 2019. After regional adaptability tests, 'Miha' was selected from 'Saebong No. 12' as an elite cultivar. The general characteristics of 'Miha' include intermediate, elliptic leaves, and strong growth. The fruits are conical and of a dark-red color. The number of leaves of 'Miha' was 21.9, which was 6.2 fewer than that of the control cultivar, 'Goha' with 28.1. The number of flower clusters of 'Miha' was similar to that of 'Goha'. The average fruit weight of 'Miha' was 13.4 g, which was 4.3 g heavier than that of 'Goha'. The fruit hardness of 'Miha' was 36.2 g·mm-2, which was 10.1 g·mm-2 harder than that of 'Goha'. The marketable yield of 'Miha' was 37,393 kg·ha-1, 156% more than that of 'Goha' with 23,970 kg·ha-1. Therefore, the new cultivar of ever-bearing strawberry 'Miha' is expected to be very popular in the export or bakery market because it is hard.