• The Korean Journal of Petroleum Geology
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• v.6 no.1_2 s.7
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• pp.25-36
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• 1998

Organic geochemical analyses were carried out in order to characterize organic matter (OM) in the sediments recovered from Korea/japan Joint Development Zone (JDZ V-1, V-3, VII-1 and VII-2) which is located in the northern end of the East China Sea Shelf Basin. Late Miocene sediments from the JDZ V-1 and V-3 wells generally contain less than $0.5\%$ of total organic carbon (TOC). However, early Miocene and Oligocene sediments show TOC values of $0.6-0.8\%$. Middle to late Miocene sediments are rich in TOC up to $20\%$ from JDZ VII-1 and JDZ VII-2 wells. The reason for this rich TOC might be attributed to the presence of coaly shales. Kerogens in the Tertiary sediments from the JDZ series wells are mainly composed of terrestrially derived woody organic matter. Elemental analyses indicate that OM from these wells can be compared to type III. Low hydrocarbon potential and hydrogen index reflect the type of OM. According to the biomarker analyses, the input of the terrestrial OM is prevalent. Oxidizing condition is also indicated by Pristane/Phytane ratio. Samples from the JDZ V-1 and V-3 wells obtain maturities equivalent to the oil generation zone around total depth, and organic matter below 3600 m from JDZ VII-1 and VII-2 wells reached dry gas generation stage. Oligocene sediments below 3500 m in the JDZ VII-1 and JDZ VII-2 wells may have generated limited amount of hydrocarbons, showing a progressive decrease in hydrogen index with depth, due to thermal degradation with increased burial. Gas shows and finely disseminated gilsonite may indicate the generation and migration of the hydrocarbons.

• Korean Journal of Ichthyology
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• v.21 no.1
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• pp.1-6
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• 2009

The effect of water temperature on fasting and post-prandial total ammonia excretion (TAN) of the starry flounder Platichthys stellatus (mean body weigh : $42.4{\pm}3.4g$) was studied. The fasting and post-prandial TAN excretions were measured under three different water temperatures (10, 15 and $20^{\circ}C$) for 24 hours using a recirculating system. In each treatment three replicates were set up and total 45 fish were used. Fish were taken to the indoor aquarium, acclimated over 10 days at three temperatures, and transferred to TAN measuring system for measurements of TAN excretion at the same temperatures. After 3 days of starvation, fasting TAN excretion was measured at each temperature. To investigate post-prandial TAN excretion, fish were hand-fed to satiation level with a commercial diet containing 50.2% crude protein for 7 days, two times daily 08 : 00 and 16 : 00 h. The fasting and postprandial TAN excretion increased with increased water temperature (p<0.05). Mean fasting TAN excretion rates at 10, 15 and $20^{\circ}C$ were 10.9, 11.2 and $12.2mg\;TAN\;kg\;fish^{-1}\;h^{-1}$, respectively. The value at $20^{\circ}C$ was higher than those at 10 and $15^{\circ}C$ (p<0.05), but there was no significant difference between $10^{\circ}C$ and $15^{\circ}C$. Mean post-prandial TAN excretion rates at 10, 15 and $20^{\circ}C$ were 33.0, 43.4 and $55.3mg\;TAN\;kg\;fish^{-1}\;h^{-1}$, respectively. Two peaks of post-prandial TAN excretions were observed, and the second peak was always greater than the first. The post-prandial TAN excretion rate reached to the maximum after 10 hours from the first feeding at $10^{\circ}C$($45.3mg\;TAN\;kg\;fish^{-1}\;h^{-1}$), $15^{\circ}C$ ($64.5mg\;TAN\;kg\;fish^{-1}\;h^{-1}$) and $20^{\circ}C$ ($83.2mg\;TAN\;kg\;fish^{-1}\;h^{-1}$), respectively. The TAN loss for ingested nitrogen at $20^{\circ}C$ (48.8%) was higher than that for $10^{\circ}C$ (43.0%) and $15^{\circ}C$ (45.7%). This study provides empirical data for estimating ammonia excretion and managing culture management of starry flounder under given temperatures.

• Korean Journal of Ichthyology
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• v.21 no.1
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• pp.7-14
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• 2009

The effect of water temperature (T) and body weight (W) on oxygen consumption of fasted starry flounder Platichthys stellatus was investigated in order to assess the metabolic response of this species at given conditions. The oxygen consumption rate (OCR) was measured under six different water temperatures (4, 7, 10, 13, 16 and $19^{\circ}C$) and at two different body weights (mean weight of fry group : 1.5 g; fingerling group : 37.4 g) at an interval of 5 minutes for 24 hours using a continuous flow-through respirometer. In each treatment three replicates were set up and a total 540 fish in fry groups and 90 fish in fingerling groups were used. The OCRs increased with increase of water temperature in both groups (p<0.001). Mean OCRs at 4, 7, 10, 13, 16 and $19^{\circ}C$ were 1386.0, 1601.7, 1741.0, 1799.2, 2239.1 and $2520.3mg\;O_2\;kg\;fish^{-1}\;h^{-1}$ in fry groups, and 83.8, 111.4, 126.3, 147.1, 187.7 and $221.3mg\;O_2\;kg\;fish^{-1}\;h^{-1}$ in fingerling groups, respectively. The OCRs decreased with increasing body weights at six different water temperatures (p<0.001). The relationship between water temperature and body weight is described by the following equation : OCR=1520.91+40.85T-49.22W ($r^2=0.95$, p<0.001). The energy loss by metabolic response increased with an increase in water temperature and a decrease in body weight (p<0.001). Mean energy loss rates by oxygen consumption at 4, 7, 10, 13, 16 and $19^{\circ}C$ were 907.9, 1046.5, 1141.6, 1177.0, 1467.3 and $1650.1kJ\;kg\;fish^{-1}\;d^{-1}$ in fry groups and 54.8, 73.0, 82.9, 96.2, 122.9 and $144.6kJ\;kg\;fish^{-1}\;d^{-1}$ in fingerling groups, respectively. The $Q_{10}$ values of fingerling groups were higher than those of fry groups at given temperature ranges. The $Q_{10}$ values at $4{\sim}7^{\circ}C$, $7{\sim}10^{\circ}C$, $10{\sim}13^{\circ}C$, $13{\sim}16^{\circ}C$ and $16{\sim}19^{\circ}C$ were 1.62, 1.32, 1.12, 2.07 and 1.48 in fry groups, and 2.59, 1.52, 1.67, 2.25 and 1.73 in fingerling groups, respectively.

• Economic and Environmental Geology
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• v.40 no.2 s.183
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• pp.153-170
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• 2007

Loading time and loading environment of the Dokdo seamounts were studied from flexure model and VGP(Virtual Geomagnetic Pole) determined by gravity and magnetic data. In spite of their similarity in size. a large difference about 50 mGal between gravity anomaly peaks of Dokdo and the Isabu Tablemount suggests different compensation degrees. Flexural modeling results show that the flexural rigidity(effective elastic thickness) of lithosphere for Dokdo is stronger(thicker) than that for the Isabu Tablemount. Also, it implies that the age of lithosphere at the time of loading of the Isabu Tablemount may be younger than that of Dokdo. Magnetic anomalies occur complicated over the Dokdo seamounts. Paleomagnetism was studied from VGP estimated by the least square and the seminorm magnetization methods with 1500 m upward continued magnetic anomalies. Age dating of Dokdo from previous study, flexural modeling, VGP, and geomagnetic polarity time scale suggest that after the cease of spreading in the Ulleung Basin, the Isabu Tablemount was formed first in normal polarity interval and followed by Dokdo. Also, they indicate that the fist large eruption of Dokdo was in normal polarity interval and the second large eruption in reversed polarity interval. The Simheungtaek Tablemount was formed in normal polarity interval between the formations of the Isabu Tablemount and Dokdo. These loading times for the Dokdo seamounts show a good coherence with the compressive stress period after the end of the opening of the East Sea. The Dokdo seamounts probably was caused by volcanism associated with the compressive stress.

• MISULJARYO - National Museum of Korea Art Journal
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• v.98
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• pp.22-53
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• 2020

This paper analyzes the contents, characteristics, and historical significance of the dedicatory inscriptions (josanggi) on the Amitabha Buddha and the Maitreya Bodhisattva statues of Gamsansa Temple, two masterpieces of Buddhist sculpture from the Unified Silla period. In the first section, I summarize research results from the past century (divided into four periods), before presenting a new perspective and methodology that questions the pre-existing notion that the Maitreya Bodhisattva has a higher rank than the Amitabha Buddha. In the second section, through my own analysis of the dedicatory inscriptions, arrangement, and overall appearance of the two images, I assert that the Amitabha Buddha sculpture actually held a higher rank and greater significance than the Maitreya Bodhisattva sculpture. In the third section, for the first time, I provide a new interpretation of two previously undeciphered characters from the inscriptions. In addition, by comparing the sentence structures from the respective inscriptions and revising the current understanding of the author (chanja) and calligrapher (seoja), I elucidate the possible meaning of some ambiguous phrases. Finally, in the fourth section, I reexamine the content of both inscriptions, differentiating between the parts relating to the patron (josangju), the dedication (josang), and the prayers of the patrons or donors (balwon). In particular, I argue that the phrase "for my deceased parents" is not merely a general axiom, but a specific reference. To summarize, the dedicatory inscriptions can be interpreted as follows: when Kim Jiseong's parents died, they were cremated and he scattered most of their remains by the East Sea. But years later, he regretted having no physical memorial of them to which to pay his respects. Thus, in his later years, he donated his estate on Gamsan as alms and led the construction of Gamsansa Temple. He then commissioned the production of the two stone sculptures of Amitabha Buddha and Maitreya Bodhisattva for the temple, asking that they be sculpted realistically to reflect the actual appearance of his parents. Finally, he enshrined the remains of his parents in the sculptures through the hole in the back of the head (jeonghyeol). The Maitreya Bodhisattva is a standing image with a nirmanakaya, or "transformation Buddha," on the crown. As various art historians have pointed out, this iconography is virtually unprecedented among Maitreya images in East Asian Buddhist sculpture, leading some to speculate that the standing image is actually the Avalokitesvara. However, anyone who reads the dedicatory inscription can have no doubt that this image is in fact the Maitreya. To ensure that the sculpture properly embodied his mother (who wished to be reborn in Tushita Heaven with Maitreya Bodhisattva), Kim Jiseong combined the iconography of the Maitreya and Avalokitesvara (the reincarnation of compassion). Hence, Kim Jiseong's deep love for his mother motivated him to modify the conventional iconography of the Maitreya and Avalokitesvara. A similar sentiment can be found in the sculpture of Amitabha Buddha. To this day, any visitor to the temple who first looks at the sculptures from the front before reading the text on the back will be deeply touched by the filial love of Kim Jiseong, who truly cherished the memory of his parents.

• Journal of the Korean Geotechnical Society
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• v.34 no.2
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• pp.19-32
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• 2018

During the process of gas hydrate extraction in the deep seabed, fine diatom particle migration occurs, which causes the seabed slope failure and the productivity deterioration of the gas hydrate. Therefore, a study related with the changes of the ground characteristics due to the fine particle migration is required. The objective of this study is to investigate the change of hydraulic properties of sand due to the migration of fine diatom particle in sandy soils. In order to simulate the sediments of the Ulleung basin gas hydrate in the East Sea, fifteen sand-diatom mixtures that have different diatom volume fractions (DVF) are prepared. During the falling head permeability tests, the coefficients of permeability are measured according to the DVF. In addition, for the simulation of the fine diatom particle migration, constant head permeability tests are conducted by applying the hydraulic pressures of 3 kPa, 6kPa, and 9 kPa on a specimen composed of two layers: a specimen with 50% DVF in upper layer and a specimen with 0% DVF in lower layer. Furthermore, the coefficient of permeability and the electrical resistivity of the migration zone are measured during the constant head permeability test. The falling head permeability tests show that the coefficient of permeability decreases as the DVF of the specimen increases. In addition, the gradient of the coefficient of permeability curve decreases in the DVF range of 10%~50% compared with that of 0%~10%, and increases above 50% in DVF. The result of constant head permeability tests shows that the coefficient of permeability decreases and electrical resistivity increases in the migration zone due to the fine diatom particle migration. This study demonstrates that fine diatom particle migration reduces the permeability of the soils and the behavior of the migration zone due to the fine diatom particle migration may be estimated based on the reversal relationship between the coefficient of permeability and the electrical resistivity.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.69 no.1
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• pp.49-60
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• 2024

A region can be divided into cultivation zones based on homogeneity in weather variables that have the greatest influence on crop growth and yield. This study classified the cultivation zone of soybean using weather indices as a prior study to classify the agroclimatic zone of soybean. Meteorological factors affecting soybeans were determined through correlation analysis over a 10 year period (from 2013 to 2022) using data from the Miryang and Suwon regions collected from the soybean yield trial database of the Rural Development Administration, Korea and the meteorological database of the Korea Meteorological Administration. The correlation between growth characteristics and the minimum temperature, daily temperature range, and precipitation were high during the vegetative growth stages. Moreover, the correlation between yield components and the maximum temperature, daily temperature range, and precipitation were high during the reproductive growth stages. As a result of k-means clustering, soybean cultivation zones were divided into three zones. Zone 1 was the central inland region and southern Gyeonggi-do; Zone 2 was the southern part of the west coast, the southern part of the east coast, and the South Sea; and Zone 3 included parts of eastern Gyeonggi-do, Gangwon-do, and areas with high altitudes. Zone 1, which has a wide latitude range, was further subdivided into three cultivation zones. The results of this study may provide useful information for estimating agrometeorological characteristics and predicting the success of soybean cultivation in South Korea.

• The Journal of the Petrological Society of Korea
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• v.10 no.2
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• pp.121-131
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• 2001

The combination of geological, structural and satellite image studies is used to make an examination of the Miocene eruptive type in the Eoil Basin, SE Korea. The basin subsided by the NW-SE extension due to NNW dextral shearing during the East Sea opening. Based on geological structures as well as lithofacies and ages of the basin-fills, it is divided into the NE subbasin and the SW subbasin which were abundantly filled with basaltic volcanics and marine sediments without volcanic materials, respectively: Syndeposional synclines and anticlines are characteristically developed in the NE subbasin, which amplitudes decrease away from the adjacent normal faults to make them into a homoclinal structure. The thicker lavas as well as the younger agglomerates and lacustrine sediments, which show circular distributions, are distributed around the axial zones of major synclines. The satellite image shows four remarkable circular structures within the NE subbasin. They are located adjacent to and along the normal faults, and they are laid almost exactly on the axial zones of the synclines as well as on the distribution area of the agglomerates and lacustrine sediments. These facts indicate that the basaltic lava effusion were conducted by the normal faults like a kind of fissure-eruption and its activity was more predominant at the sites in where the synclines are developed. More active effusion of lava became a reason for deeper subsidence to make differential subsidence and syndepositional folding adjacent to and along the normal faults. Hence, we suggest that a nested cauldron structure was formed in the NE subbasin of the Eoil Basin, and that the volcanism made the subbasin to be a lava pond and controlled the process of filling and sedimentation in the subbasin.

• Korean Journal of Ichthyology
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• v.22 no.3
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• pp.147-153
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• 2010

A study was carried out to examine the effect of water temperature on daily pattern and rate of total ammonia nitrogen (TAN) excretion in juvenile Pacific cod Gadus macrocephalus (mean body weight: $36.5{\pm}0.8\;g$) under fasting and feeding conditions. Fish were acclimated over 10 days under three different water temperatures (9, 11 and $13^{\circ}C$), and transferred to TAN measuring system under each water-temperature condition. After 72 hours of starving, fasting TAN excretion was measured at each temperature. To investigate post-prandial TAN excretion, fish were hand-fed with a commercial diet containing 40.6% crude protein for 7 days, two times daily at 08:00 and 16:00 h. Water was sampled from both the inlet and outlet of the fish chamber every 2 h over a 24-h period. Both fasting and post-prandial TAN excretion increased with increased water temperatures (p<0.05). Mean fasting TAN excretion rates at 9, 11 and $13^{\circ}C$ were 9.3, 11.0 and $11.9\;mg\;TAN\;kg\;fish^{-1}\;h^{-1}$, respectively. The value of $9^{\circ}C$ was lower than those of 11 and $13^{\circ}C$ (p<0.05), but there was no significant difference between $11^{\circ}C$ and $13^{\circ}C$. Mean post-prandial TAN excretion rates at 9, 11 and $13^{\circ}C$ were 23.0, 31.6 and $45.4\;mg\;TAN\;kg\;fish^{-1}\;h^{-1}$, respectively. A peak value of post-prandial TAN excretion rate occurred after 2 h from each feeding, and the second value is always higher than the first value. Maximum post-prandial TAN excretion rate occurred after 10 h from the first feeding at $9^{\circ}C$ (mean $38.0\;mg\;TAN\;kg\;fish^{-1}\;h^{-1}$), $11^{\circ}C$ ($52.9\;mg\;TAN\;kg\;fish^{-1}\;h^{-1}$) and $13^{\circ}C$ ($77.5\;mg\;TAN\;kg\;fish^{-1}\;h^{-1}$), respectively. The TAN loss for ingested nitrogen at $9^{\circ}C$ (43.9%) was lower than those of $11^{\circ}C$ (46.4%) and $13^{\circ}C$ (48.4%). The overall results indicate that water temperature exhibits a significant effect on the nitrogen excretion of juvenile Pacific cod.

• Korean Journal of Environment and Ecology
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• v.25 no.3
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• pp.327-357
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• 2011

This study compared the species composition and distribution of the forest communities between Korea and Japan using vegetation releve database. The study included the eastern and southern Korean Peninsula, Is. Jeju, Is. Ulreung, northern Kyushu, central part of Japan and Is. Tsushima and divided in fourteen region with major mountain as the center. Seventy-nine forest communities were classified by tabular comparison with the total of 1844 releves. In the composition table, fifty-four groups of plant species were listed. Some grew in one area exclusively, while others were present in multiple locations. This study showed the similarity and heterogeneity of species composition among study areas. We grouped fourteen types showing similar physiognomy for forest communities. The physiognomical features of the vertical vegetation zones in the study area were similar, however, dominant species and species composition were different between the regions. In the lowland zone, Castanopsis-Type dominated by Castanopsis cuspidata var. sieboldii or Castanopsis cuspidata were distributed in the study area except for northern part of the Korean Peninsula and Is. Ulreung. Additionally, Persea thunbergii-Type was distributed widely in the lowest part of the study area, however, it showed the simplification of the species composition in the Korean Peninsula and Is. Ulreung. In the hilly zone, evergreen forest composed by Abies firma-Type distributed in northern Kyushuand Is. Tsushima, but it was absent in the other study region. The difference in forest community was conspicuous, especially in the montane zone. Deciduous broadleaved forests composed Quercus(D)-Type and Fagus-Type widely distributed in the montane of study area. However, forest community dominated by Quercus mongolica and Fagus multinervis flourished in Korea. On the otherhand, forest community dominated by Quercus mongolica var. grosseserrata, Fagus crenata and F. japonica distributed in Japan. In the sub-alpine zone, evergreen coniferous forest composed Abies-Quercus(D)-Type, Abies koreana-Type, and Pinus pumila-Type were distributed in the Korean Peninsula and Is. Jeju. Forests composed Taxus cuspidata var. nana-Type, Abies mariesii-Type, and Pinus pumila-Type distributed in the central part of Japan. As a result of DCA ordination, evergreen broadleaved forests of the whole study area showed the lower scores along the first axis, while deciduous and coniferous forests showed the higher scores. The forest types of western part of Japan were located the higer scores, forest types of the Korean Peninsula were located the lower scores, and forest types of Is. Jeju located in the middle. Warmth index (WI) and Annual range of temperature in climate factor were highly correlated on the first axis. The first axis reflected the gradient from oceanic climatic to continental one. The higher the altitude and further geographically, the lower the similarity among communities and the peculiarity of community appeared stronger. The historical background reflecting local flora has strongly influenced on development of community.