• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.4
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• pp.457-467
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• 2019

To investigate the long-term variation characteristics of nutrients in the east coast of Korea, water temperature, salinity, dissolved oxygen, and nutrients were measured at three stations of Sokcho, Jukbyeon and Gampo coasts for five years from 2013 to 2017. For five years, the water temperature of the East Sea coast was in the range of $1.2{\sim}28.8^{\circ}C$, the salinity was in the range of 30.63~34.79 and the dissolved oxygen (DO) was in the range of 3.53~7.64 mL/L. Distribution and variation of the water environment factors in the study area were determined by the vertical stratification of water column and distribution of water temperature. The high DO concentration in Sokcho coast From 2015 to August 2016 is presumed to be the result of the southward inflow of North Korean Cold Water (NKCW). Concentrations of dissolved inorganic nitrogen (DIN, $NH_4-N+NO_2-N+NO_3-N$) ranged $0.11{\sim}24.19{\mu}M$, phosphate concentration ranged $0.01{\sim}1.75{\mu}M$, and silicate ranged $0.17{\sim}32.80{\mu}M$. The N:P ratio was in the range of 0.7~54.3 (mean 15.2) and the N:P slope was in the range of 11.67~13.75. The N:P ratios in this study were lower than the Redfield ratio (16), indicating that nitrate did act as a limiting factor in phytoplankton growth. The correlation ($R^2$) of total N:P ratio was as high as 0.95, indicating that the effect of the surrounding land or non-point sources was not significant. In conclusion, the spatial and temporal variation of nutrients in the east coast of Korea was determined by the vertical mixing of water mass with thermocline and mainly affected by physical factors such as influx of external water masses and coastal upwelling, and the influences from inflows from the land were minimal.

• Journal of Plant Biotechnology
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• v.46 no.2
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• pp.127-135
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• 2019

The purpose of this study was to investigate suitable parts for callus induction and optimal concentrations of growth regulators, contained in the medium affecting shoot and rooting for in vitro mass production of Haworthia truncata. Leaves and flower bud showed 100% callus formation rate at NAA $1{\sim}2mgL^{-1}$ treatment, and NAA $1mgL^{-1}$ + TDZ $2mgL^{-1}$ treatment. The flower stalk showed 75% callus formation rate, at NAA $2mgL^{-1}$ + TDZ $2mgL^{-1}$ treatment in H. truncata. While the rate of callus formation was high in leaves and flower bud, leaves were the most efficient in obtaining most culture parts. Shoot induction rate from callus was highest, at NAA $0.1mgL^{-1}$ treatment in H. truncata. Additionally, the number of shoots formation was 66.3 shoots high, in NAA $1mgL^{-1}$ + BA $0.1mgL^{-1}$ treatment in H. truncata. In the case of acclimatization of regenerated plant, growth characteristics did not show significant difference (95%) shading with respect to the different ratio of substrate mixture, and it was determined that would be appropriate, considering plant height and appearance preference of H. truncata. It was established that optimization of culture condition, was responsible for mass propagation in vitro cultures of H. truncata.

• Journal of Food Hygiene and Safety
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• v.34 no.4
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• pp.404-411
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• 2019

This study was carried out to investigate the antioxidant effects of extracts from 9 species of forest plants in Korea. DPPH, ABTS, $NaNO_2$, hydrogen peroxide radical scavenging activity and reducing power activity were evaluated to measure the antioxidant activities of plant extracts. As a result, Geranium thunbergii has been identified as the most effective antioxidant resource. Also, total phenolic content was highest in Geranium thunbergii ($303.94{\pm}0.63mg\;GAE/g$) among 9 species extracts. Total flavonoid content was highest in Rosa multiflora ($24.32{\pm}0.22mg\;QE/g$) and proanthocyanidin content was highest in Vitis ficifolia ($279.00{\pm}4.58mg\;CE/g$) among 9 species extracts. In addition, the protective effect of plant extracts in $H_2O_2-induced$ human dermal fibroblast (HDF) cell systems were also assessed. Significant protective effects in $H_2O_2-induced$ human dermal fibroblast (HDF) cell systems were found in all plant extracts, especially in Geranium thunbergii. These results suggest that Geranium thunbergii could be a potential natural resource for antioxidant activity.

• Korean Journal of Heritage: History & Science
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• v.44 no.4
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• pp.56-69
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• 2011

A Gamsil is an ritual instrument which enshrine the ancestral tablets of four lines from late great-great-grandfather and grandmother to late father and mother. This has their soul. Juja's "Garye" informs its structure pattern. It is placed in Sadang and takes the form of a perfectly square box. It partitions four rooms and enshrine an ancestral tablet room by room. They get the ancestral tablets line up from west to east. And they also enshrine the ancestral tablets without his descendant together in Gamsil. A Gamsil is a space to enshrine the ancestral tablets and to place an order within a family. A social status and A family economic power become a standard in making and managing Sadang. Kingdom in Joseon period limited the ancestral tablets considering of his degree of official rank which descendant enshrined. A official servant can be stable economically in getting a stipend and build sadang in the house. While household a little in economic enshrine the ancestral tablets at a Gamsil placed at the a space of private home. His personal circumstances make size and pattern, place change in relation to Gamsil. A Gamsil looks like house in structure and pattern. It has the immortality of the soul. And it changed from a table size to a ancestral tablet size. This Gamsil is comfortable to move and is made considering of the width and height of household. The transition of Gamsil means institutions is in close to a family economic power in social change. Kingdom in Joseon early period makes a policy of a Gamyo's build and an ancestral enshrine in basement of Juja's "Garye". The transition of Gamsil gave a common people limitted socially and institutionally the service of late four lines. Most of people enshrine the ancestral tablets of their four lines in approaching of in the late of Joseon Dinasty. They compromise on their reality and cause. The transition of Gamsil implied many different things in social ; the authenticity search and a dignity expression of his family, the foundation for the diffusion of an ancestral service, a space sharing with ancestor and descendent, the increment of a family economic power etc.

• Korean Journal of Heritage: History & Science
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• v.46 no.3
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• pp.16-31
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• 2013

This study addresses how the main group of community ritual changed as the regional community changed during the period of Japan's colonial rule of Korea with emphasis on Gwanseongmyo in Jangchung-dong, Seoul. First, almost every regional community was changed because of city planning which was carried out by Japan in Korea for colonial exploitation and for the use of military bases. Mapo-dong and Seobinggo-dong were the appropriate examples. The city planning projects by the Japanese colonial government selected Jangchung-dong as the place of settlement of many Japanese people. The stream, Cheonggyecheon, made a border between the Korean and Japanese settlements and the traditional system of regional community in Jangchung-dong was changed and reorganized considerably. Second, the Japanese government used the rituals of regional community purposefully to combine them with the ceremony in the Japanese shrine. Those who supported Japan performed the regional rituals and tried to follow the policy of 'Rule of Culture' required by the Japanese colonial government. However, most regional rituals continued as they were before Japan's colonial rule of Korea without any change. Under this new trend the ritual of Gwanseongmyo was changed from the ritual for worshipping Guan Yu to that of the regional community. Last, the main groups that led the rituals of regional community were diversified during the period of Japan's colonial rule of Korea. In other words, the rituals of community used to be led by the families that lived in the region for generations before Japan's colonial rule of Korea. However, they were later led by various groups that emerged as a result of the colonial rule, urbanization, commercial development, regional differentiation, and so on. As an example,Yeongsinsa of Gwanseongmyo,which was the main group to lead the ritual of Gwanseongmyo, shows that the regional community rituals were extended to worshipping Guan Yu. The members of the main group to lead the ritual were pro-Japanese senior officials who were formerly military officers. This shows that the main groups leading the regional community rituals were further diversified.

• Korean Journal of Heritage: History & Science
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• v.45 no.2
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• pp.4-19
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• 2012

There remain many royal tombs of the Goryeo Dynasty in Gaeseong and Ganghwa. During the Goryeo Dynasty, these royal tombs were taken over tradition of tomb construction style from previous generation, and they completed their own inventive style. Furthermore they handed down those style to the Joseon Dynasty. The area of tomb was divided into 3 or 4 steps, and stone figures and T-shaped houses for sacrifice were arranged on each steps. It was the stone chamber of lateral opening style which had an entrance to southward, and it was formed as a rectangular box-shaped with a pile of stone walls and a flat ceiling. There was a coffin stand in the middle of floor, and traditional bricks were around them. The wall side and ceiling had been whitewashed and painted pictures. These are general characteristics for the tomb construction style of the Goryeo Dynasty. By the way, we can notice a number of features except those general things with inspection in detail. In early days, we confirmed 1step-parallel fulcrum ceiling, coffin stand of all in one stone, bier of burial artifact, and mural of plant material as a set, but they were changed as flat ceiling, Red-stone wall with rectangular stone, coffin stand set as stone pillar through the period of transitional form as of in the late 12th century. In case of several royal tombs, the fragments of king's epitaph which were confirmed from tombs could be defined owners clearly, and there were considerable timing difference between the large numbers of celadons which were excavated with the fragments of king's epitaph and recording chronologically of stone chamber structure. The reason for timing difference is that posterity artifacts were buried through repairing courses by occasion of destruction caused by robbing of the royal tombs. Meanwhile I inferred the existing hypothesis about owners of royal tombs and autonym ones in comparison the burial spot direction of hypothesis ones and outcomes of excavation. Therethrough, some hypothesis about owners of royal tombs such as Myung-neung which was assumed as tomb of the King Choongmok were not correct.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.3
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• pp.83-91
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• 2019

The purpose of this study is to assess a fire-damaged concrete structure using a digital camera and image processing software. To simulate it, mortar and paste samples of W/C=0.5(general strength) and 0.3(high strength) were put into an electric furnace and simulated from $100^{\circ}C$ to $1000^{\circ}C$. Here, the paste was processed into a powder to measure CIELAB chromaticity, and the samples were taken with a digital camera. The RGB chromaticity was measured by color intensity analyzer software. As a result, the residual compressive strength of W/C=0.5 and 0.3 was 87.2 % and 86.7 % at the heating temperature of $400^{\circ}C$. However there was a sudden decrease in strength at the temperature above $500^{\circ}C$, while the residual compressive strength of W/C=0.5 and 0.3 was 55.2 % and 51.9 % of residual strength. At the temperature $700^{\circ}C$ or higher, W/C=0.5 and W/C=0.3 show 26.3% and 27.8% of residual strength, so that the durability of the structure could not be secured. The results of $L^*a^*b$ color analysis show that $b^*$ increases rapidly after $700^{\circ}C$. It is analyzed that the intensity of yellow becomes strong after $700^{\circ}C$. Further, the RGB analysis found that the histogram kurtosis and frequency of Red and Green increases after $700^{\circ}C$. It is analyzed that number of Red and Green pixels are increased. Therefore, it is deemed possible to estimate the degree of damage by checking the change in yellow($b^*$ or R+G) when analyzing the chromaticity of the fire-damaged concrete structures.

• Korean Journal of Heritage: History & Science
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• v.42 no.2
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• pp.154-169
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• 2009

Korea is famous for a number of stone pagodas. In particular, it is noticeable that the stone pagodas came after wooden pagodas in all the Kingdoms of Goguryeo, Baekje, and Silla. Since the advent of wooden pagodas, it was during the latter half period of Three Kingdoms(especially, in the early Seventh century) that the first stone pagoda appeared at Mireuksa Temple site in imitation of the wooden ones. Now that no one can deny that Korean stone pagodas have developed, imitating the wooden pagodas. It is also obvious that the Stone Pagoda at Mireuksa site is the prototype of Korean stone pagodas. However, this study casts doubt on the theory that the stone pagodas in the Silla Kingdom originated not from the wooden pagodas, but from the brick pagodas, whereas the stone pagodas in Baekje Kingdom which has been said to come from the wooden ones. The fact that the temples and pagodas in both Baekje and Silla were erected by the same builders and technicians is one of the evidences supporting the assertion of the study. This study, accordingly, examines on the origin of the Silla pagodas by supposing the two genealogies. The first one can be summarized in chronological order as follows: starting from wooden pagodas, Stone Pagoda at Mireuksa site, Stone Pagoda at Jungrimsa site, Stone Pagoda at Gameunsa site, and Stone Pagoda at Goseonsa site. The second one, on the other hand, runs as follows: starting from bick pagodas, Stone Pagoda at Bunhwangsa, Uiseong Tapri five-storied Stone Pagoda, Seonsan Jukjang-ri five-storied Stone Pagoda, and Seonsan Naksan-ri three-storied Stone Pagoda in order. As the above genealogies show, the origin of the stone pagodas has been an controversy, especially because of the two different points of view: the one is that the roof-supporting strata(Okgaesuk-Bachim) originated from the brick structure and the ancient tomb ceiling of Goguryeo Kingdom, and the other is that the strata is a sort of the simplified design of the wooden roof structure. This study, however, takes note of the difference in length of the strata between the brick pagodas and the stone pagodas; the former stretches out its strata longer than the latter. Consequently, the study points out that the roof-supporting strata of the stone pagodas is originally a sort of modification of the wooden roof structure.

• Korean Journal of Heritage: History & Science
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• v.42 no.3
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• pp.66-87
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• 2009

The definition of the structure of wooden chamber tomb(piled stone-type) is as follows. It is a tomb with wooden chamber, and stones were piled on top of the wooden chamber, and then a wooden structure was placed on top of the piled stones, and more stones were piled on top of the wooden structure, and sealed with clay. Of course this definition can vary according to periods, the buried, etc. Gyeongju-style piled stone type wooden chamber tombs have some distinguished characteristics compared to general definition of piled stone type wooden chamber tombs. Outside the wooden chamber, either stone embankments or filled-in stones were layed out, and pilet-in stones are positioned right above the wooden chamber, and almost every class used this type, and finally, it is exclusively found in Gyeongju area. First generations of this Gyeongju-style piled stone type wooden chamber tombs appeared in first half of 5th century. These tombs inherited characteristics like ground plan, wooden chamber, double chamber(inner chamber and outer chamber), piled stones, burial of the living with the dead, piled stones, from precedent wooden chamber tombs. However these tombs have explicit new characteristics which are not found in the precedent wooden chamber tombs such as stone embankments, wooden pillars, piled stones(above ground level), soil tumuluses. stone embankments and wooden pillars are exclusively found on great piled stone type above-ground level wooden chamber tombs such as the Hwangnamdaechong(皇南大塚). Stone embankments, wooden pillars, piled stones(above ground level) are all elements of building process of soil tumuluses. stone embankments support outer wall of above-ground level wooden chambers and disperse the weight of tumuluses. Wooden pillars functioned as auxiliary supports with wooden structures to prevent the collapse of stone embankments. Piled stones are consists of stones of regular size, placed on the wooden structure. And after the piled stones were sealed with clay, tumulus was built with soil. Piled stones are unique characteristics which reflects the environment of Gyeongju area. Piled stone type wooden chamber tombs are located on the vast and plain river basin of Hyeongsan river(兄山江). Which makes vast source of sands and pebbles. Therefore, tumulus of these tombs contains large amount of sands and are prone to collapse if soil tumulus was built directly on the wooden structure. Consequently, to maintain external shape of the tumulus and to prevent collapse of inner structure, piled stones and clay-sealing was made. In this way, they can prevent total collapse of the tombs even if the tumulus was washed away. The soil tumulus is a characteristic which emerges when a nation or political entity reaches certain growing stage. It can be said that after birth of a nation, growing stage follows and social structure will change, and a newly emerged ruling class starts building new tombs, instead of precedent wooden chamber tombs. In this process, soil tumulus was built and the size and structure of the tombs differ according to the ruling class. Ground plan, stone embankments, number of the persons buried alive with the dead, quantity and quality of artifacts reflect social status of the ruling class. In conclusion, Gyeongju-style piled stone type wooden chamber tombs emerged with different characteristics from the precedent wooden chamber tombs when Shilla reached growing stage.

• Korean Journal of Heritage: History & Science
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• v.41 no.1
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• pp.109-125
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• 2008

Recently, there has been an increase in excavation studies of wood pagodas from the Three Kingdoms and Unified Shilla periods and new data related to wood pagoda erection are being found bringing about progress in research on this field. In other words, studies on wooden pagodas in Korea were composed mainly of flat, axis construction techniques and sarijangeomgu, but by acquiring new data, it has now become possible to study not only the stylobate construction procedure and transition, but also studies on restoring wooden pagodas. Furthermore, pagoda sites similar to this were found in China and Japan as well, making it possible to make comparative studies among ancient wooden pagodas possible. In this paper, the main remains were set as Baekjae wooden pagodas, which were the most frequently studied and among the wooden pagodas, the simcho (central base stone) and sarira housing locations. In result, simcho can be found changing its position from underground ${\rightarrow}$ halfway underground ${\rightarrow}$ above ground. Baekjae wooden pagodas up until the mid sixth century located at Neungsan-ri saji (AD 567) and Wangheungsaji (AD 577) had its simcho located underground and later it was constructed halfway underground and then above ground. It was confirmed that in the 7th century, it became customary to place above ground as seen in the Jaeseoksaji (AD639) and Hwangnyongsaji (AD645) wooden pagoda sites. The sarira was usually located on the south side of the simcho, but gradually changed to the center. In particular, sarira were combined in the simcho in the mid sixth century at the Wangheungsaji. This is approximately 11 years earlier than the Bijosa (AD 588) simcho found in Japan and this was not found even in the simcho of wooden pagodas in Yeongnyeongsa (AD 516) and Jopaengseong temple (AD 535~561) of China showing that the Wangheungsaji simcho was the earliest of its kind.