• Economic and Environmental Geology
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• v.54 no.2
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• pp.299-308
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• 2021

Fe(II) released from mining activities is precipitated as various Fe(III)-oxyhydroxides when exposed to an oxidizing environment including mine drainage. Ferrihydrite, one of the representative precipitated Fe(III) minerals, is easy to adsorb heavy metals and other pollutants due to the large specific surface area caused by very low crystallinity. Ferrihydrite is transformed to thermodynamically more stable goethite in the natural environment. Hence, information on the transformation of ferrihydrite to goethite and the related mobility of heavy metals in the acid mine drainage is important to predict the behaviors of those elements during ferrihydrite to goethite transition. The behaviors of heavy metals during the transformation of ferrihydrite to goethite were investigated for core samples collected from an AMD treatment system in the Heungjin-Taemaek coal mine by using X-ray diffraction (XRD), chemical analysis, and statistical analysis. XRD results showed that ferrihydrite gradually transformed to goethite from the top to the bottom of the core samples. Chemical analysis showed that the relative concentration of As was significantly high in the core samples compared with that in the drainage, indicating that As was likely to be adsorbed strongly on or coprecipitated with iron oxyhydroxide. Correlation analysis also indicated that As can be easily removed from mine drainage during iron mineral precipitation due to its high affinity to Fe. The concentration ratio of As, Cd, Co, Ni, and Zn to Fe generally decreased with depth in the core samples, suggesting that mineral transformation can increase those concentrations in the drainage. In contrast, the concentration ratio of Cr to Fe increased with depth, which can be explained by the chemical bond of iron oxide and chromate, and surface charge of ferrihydrite and goethite.

• Korean Journal of Heritage: History & Science
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• v.53 no.4
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• pp.216-233
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• 2020

This study set out to review tomb culture in the Gyeongju region during the Bronze Age, and also examine the patterns of dolmens during their end phase. For these purposes, the study analyzed 18 tomb relics from the Bronze Age and nine from the early Iron Age. Gyeongju belongs to the Geomdan-ri cultural zone. Approximately 120 tombs from the Bronze Age have been excavated in the Gyeongju region. There are fewer tombs than dwellings in the region, which is a general characteristic of the Geomdan-ri cultural zone. Although the number of tombs is small, the detailed structure of the dead body is varied. During the Bronze Age, tombs in the Gyeongju region were characterized by more prolific construction of pit tombs, dolmens with boundaries, and stacked stone altars than were the cases in other areas. There is a great possibility that the pit tombs in the Gyeongju region were influenced by their counterparts in the northeastern parts of North Korea, given the spindle whorl artifacts buried at the Dongsan-ri sites. Dolmens with boundaries and stacked stone altars are usually distributed in the Songguk-ri cultural zone, and it is peculiar that instances of these are found in large numbers in the Gyeongju region as part of the Geomdanri cultural zone. Even in the early Iron Age, the building of dolmens with boundaries and stacked stone altars continued in the Gyeongju region under the influence of the Bronze Age. A new group of people moved into the area, and they crafted ring-rimmed pottery and built wooden coffin tombs. In the early Iron Age, new rituals performed in high places also appeared, and were likely to provide venues for memorial services for heavenly gods in town-center areas. The Hwacheon-ri Mt. 251-1 relic and the Jukdong-ri relic are ruins that exhibit the aspect of rituals performed in high places well. In these rituals performed in high places, a stacked stone altar was built with the same form as the dolmens with boundaries, and a similar rock to the cover stone of a dolmen was used. People continued to build and use dolmens with boundaries and stacked stone altars while sustaining the Bronze Age traditions, even into the early Iron Age, because the authority of dolmens was maintained. Some dolmens with boundaries and stacked stone altars, known as being Bronze Age in origin, would have continued to be used in ritual practices until the early Iron Age. Entering the latter half of the second century B.C., wooden coffin tombs began to propagate. This was the time when the southern provinces, including the Gyeongju region, were included in the East Asian network, with the spread of ironware culture and the arrival of artifacts from central China. Around this time, dolmen culture faded into history with a new era beginning in its place.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.29 no.1
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• pp.59-70
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• 2011

The purpose of this study is to present raw data to systematically and rationally manage the protected trees located in Changwon-si, Korea. This study investigated about the present condition and the information of location, individual, management, health and soil. The results are as follows. The protected trees were located in 26 spots, and species of trees were 9 taxa; Zelkova serrata, Celtis sinensis, Aphananthe aspera, Ginkgo biloba, Carpinus tschonoskii, Pinus densiflora for. multicaulis, Quercus variabilis, Pinus densiflora and Salix glandulosa. In protected tree types, shade trees were the most, and the majority of theirs were 200 years or more in age. The range of altitude was 14~173m, and the number of trees located in flat fields was the most. For location types, village and field and mountain were presented in the order and, in land use, land for building was the most. The range of height was 8.0~30.0m, 0.6~5.1m in crown height, 240~700cm in diameter of breast and 210~800cm in diameter of root. In case of crown area, Zelkova serrata of No.5 was most large. The status boards were mostly installed except No.23 and No.26. The sites with fence were 9 spots, and the site with stonework were 14 spots. The sites with the support beam were 5 spots, and most sites were not covered up with soil. The materials of bottom were soil, gravel and vegetation in the order. The range of withering branch rate was 0~40%, and peeled bark rate was 0~60%. The sites made holes were 23 spots, and the hole size of Aphananthe aspera of No.12 was the largest. The sites disturbed by human trampling were 7 spots, the sites by disease and insects of 2 spots, the sites by injury of 23 spots and the sites by exposed roots of 13 spots. In the results of soil analysis, there showed that acidity was pH 4.5~8.0, organic matter content of 3.5~69.8g/kg, electrical conductivity(EC) of 0.11~2.87dS/m, available $P_2O_5$ of 3.0~490.6mg/kg, exchangeable K of 0.10~1.05cmol+/kg, exchangeable Ca of 1.41~16.45cmol+/kg, exchangeable Mg of 0.37~1.96cmol+/kg, exchangeable Na of 0.25~2.41cmol+/kg and cation exchange capacity(C.E.C) of 8.35~26.55cmol+/kg.

• The Journal of Korean Philosophical History
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• no.52
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• pp.131-155
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• 2017

While the lecture activities in Simwonsa, Ganjae Jeon Wu(1841~1922) has established a "law of lecture activities" which was an ritual between a teacher and pupil, between the couple. Through this way he expected to recover the former ritual, even within their own school. In 1884 he built a "law of Sidong school", meaning to build a large object, elementary scholarship will serve as the rules of conduct, and argued that human nature mainly served to the core in the course of study. Ganjae in Mungyeong area was also discussing studies with Song Byeong-hwa(1852~1916) and received correspondence with scholars in areas related to Mungyeong. They were Kim Jae-kyung(1841~1926) and Park Se-hwa (1834~1910). Ganjae had also some big national events on the sojourn time in Mungyeong. In 1882 there were army incident, in 1884 there were a command of the government that people must pull on western clothes. Ganjae did not follow the command of the government. Someone asked "Can we not follow the command of the government?" Ganjae replied "We have a right to resist to the illegal command of the government. There were also 1884's Gapsin-coup, Ganjae saw that we must defend the country by rejecting foreign power and keeping our rituals. Given the above, the timing that Ganjae lectured in Mungyeong personally was a time that provided a clue to establish his core ideas. Nationally it was a time that must defend the country from foreign nations. Ganjae had faith that for keeping the country we must keep firmly our own rituals.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.38 no.4
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• pp.101-110
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• 2020

This study was conducted through the analysis of literature and on-site research as a case study of 14 artists' gardens with traditional themes presented at the garden fair. With Focusing on the design process for determining traditional reproduction, the following characteristics and implications were derived by analyzing the design goals, selection of subjects for traditional reenactment, determination of methods for reproduction, and design stages of landscape components. First, the pattern of selecting traditional structures as subjects for reproduction in many artist gardens can be understood as an advantage of being suitable for narrow sites and having remarkable topic communicability. They directly delivered the design intent by adding the names of traditional structures such as Madang, Wool, Buttumak, Jangdokdae, Chuibyeong and Seokgasan. Works expressed indirectly, such as Wall, Korean Garden, Suwon, and Seoul craftsmen, have relatively weak topic communicability. There were also symbolic representations of objects to be reproduced, such as Seonbi, marginal spaces, and Pung-lyu. Second, while reproducing Hanok Madang, separate the gardens paved with grass and stone, the fortress wall of Suwon Hwaseong and the northwest Gongsimdon of the watchtower. Also the garden with a miniature version of the extraneous Yong-yeon and the garden, which was reproduced as a low decorative wall in the rest area based on Nakan-Eupseong Fortress, shows the need for a deep understanding of tradition. On the other hand, the reproducting works of choosing the location of the traditional garden, the Korean Garden showed the importance of systematic arrangement with the surrounding environment, the beauty of the space in the courtyard of Hanok, the beauty of the slowness enjoyed by the scholars and the reenactments of the Pung-lyu culture of Moonlight boating are not only imitating traditional structures but also spreading understanding of tradition to garden culture and sentiment. Third, there were many works that reconstructed the real-size traditional structure in a straightforward way in relation to design. The garden was divided into Chuibyeong and the living space was decorated with Buttumak, chimneys, and gardens, and facilities representing Gyeongbokgung Palace, Soswaewon, and Seoseokji were systemically arranged. However it recognized the importance of selecting the key design elements, constructing the elevation of the structure, and the sense of scale of the space from works that reproduced the large Suwon Hwaseong and Nakan-Eupseong in an abstract way. While there are examples gardens of Hanok yards and Bazawul, which are far from the original image among the gardens that chose the dismantling method, the Blank-space garden expressed only by a frame composed of cubes, and Seonbi's Sarangbang garden, that permeated the moonlight with many traditional structures are the positive examples. The Seoul Artisan Garden, Jikji Simche Garden and Pung-lyu Garden, which display modernly designed landscape components, need an explanation to understand the author's intention.

• Economic and Environmental Geology
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• v.54 no.3
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• pp.373-387
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• 2021

In this study, the impact of clustered groundwater usage facilities and the proper amount of groundwater usage in the Daejeong-Hangyeong watershed of Jeju island were evaluated based on the data-driven analysis methods. As the applied data, groundwater level data; the corresponding precipitation data; the groundwater usage amount data (Jeoji, Geumak, Seogwang, and English-education city facilities) were used. The results show that the Geumak usage facility has a large influence centering on the corresponding location; the Seogwang usage facility affects on the downstream area; the English-education usage facility has a great impact around the upstream of the location; the Jeoji usage facility shows an influence around the up- and down-streams of the location. Overall, the influence of operating the clustered groundwater usage facilities in the watershed is prolonged to approximately 5km. Additionally, the appropriate groundwater usage amount to maintain the groundwater base-level was analyzed corresponding to the precipitation. Considering the recent precipitation pattern, there is a need to limit the current amount of groundwater usage to 80%. With increasing the precipitation by 100mm, additional groundwater development of approximately 1,500m³-1,900m³ would be reasonable. All the results of the developed data-driven estimation model can be used as useful information for sustainable groundwater development in the Daejeong-Hangyeong watershed of Jeju island.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.16 no.3
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• pp.13-29
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• 2021

The purpose of this study was to analyze the spatial distribution and location factors of startups by generation (young and middle-aged) in Seoul. To this end, a research model was established that included factors of industry, population, and startup institutions by generation in 424 administrative districts using the Seoul Business Enterprise Survey(2018), which includes data on the age group of entrepreneurs. As an analysis method, descriptive statistics were conducted to confirm the frequency, average and standard deviation of startups by generation and major variables in the administrative districts of Seoul, and spatial distribution and characteristics of startups by generation were analyzed through global and local spatial autocorrelation analysis. In particular, the spatial distribution of startups in Seoul was confirmed in-depth by categorizing and analyzing startups by major industries. Afterwards, an appropriate spatial regression analysis model was selected through the Lagrange test, and based on this, the location factors affecting startups by generation were analyzed. The main results derived from the research results are as follows. First, there was a significant difference in the spatial distribution of young and middle-aged startups. The young people started to startups in the belt-shaped area that connects Seocho·Gangnam-Yongsan-Mapo-Gangseo, while middle-aged people were relatively active in the southeastern region represented by Seocho, Gangnam, Songpa, and Gangdong. Second, startups by generation in Seoul showed various spatial distributions according to the type of business. In the knowledge high-tech industries(ICT, professional services) in common, Seocho, Gangnam, Mapo, Guro, and Geumcheon were the centers, and the manufacturing industry was focused on existing clusters. On the other hand, in the case of the life service industry, young people were active in startups near universities and cultural centers, while middle-aged people were concentrated on new towns. Third, there was a difference in factors that influenced the startup location of each generation in Seoul. For young people, high-tech industries, universities, cultural capital, and densely populated areas were significant factors for startup, and for middle-aged people, professional service areas, low average age, and the level of concentration of start-up support institutions had a significant influence on startup. Also, these location factors had different influences for each industry. The implications suggested through the study are as follows. First, it is necessary to support systematic startups considering the characteristics of each region, industry, and generation in Seoul. As there are significant differences in startup regions and industries by generation, it is necessary to strengthen a customized startup support system that takes into account these regional and industrial characteristics. Second, in terms of research methods, a follow-up study is needed that comprehensively considers culture and finance at the large districts(Gu) level through data accumulation.

• Korean Journal of Mineralogy and Petrology
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• v.34 no.1
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• pp.31-40
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• 2021

The hydrogen in nominally anhydrous mineral is known to be associated with lattice defects, but it also can exist in the form of water and hydroxyl groups on the large surface of the nanoscale particles. In this study, we investigate the effectiveness of 1H solid-state nuclear magnetic resonance (NMR) spectroscopy as a robust experimental method to quantify the hydrogen atomic environments of amorphous silica nanoparticles with varying relative humidity. Amorphous silica nanoparticles were packed into NMR rotors in a temperature-humidity controlled glove box, then stored in different atmospheric conditions with 25% and 70% relative humidity for 2~10 days until 1H NMR experiments, and a slight difference was observed in 1H NMR spectra. These results indicate that amount of hydrous species in the sample packed in the NMR rotor is rarely changed by the external atmosphere. The amount of hydrogen atom, especially the amount of physisorbed water may vary in the range of ~10% due to the temporal and spatial inhomogeneity of relative humidity in the glove box. The quantitative analysis of 1H NMR spectra shows that the amount of hydrogen atom in amorphous silica nanoparticles linearly increases as the relative humidity increases. These results imply that the sample sealing capability of the NMR rotor is sufficient to preserve the hydrous environments of samples, and is suitable for the quantitative measurement of water content of ultrafine nominally anhydrous minerals depending on the atmospheric relative humidity. We expect that 1H solid-state NMR method is suitable to investigate systematically the effect of surface area and crystallinity on the water content of diverse nano-sized nominally anhydrous minerals with varying relative humidity.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.40 no.6
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• pp.603-611
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• 2020

This study collected and analyzed transportation card data in order to better understand the operation and usage of city buses in Ulsan Metropolitan City in Korea. The analysis used quantitative and qualitative indicators according to the characteristics of the data, and also the categories were classified as general status, operational status, and satisfaction. The existing city bus survey method has limitations in terms of survey scale and in the survey process itself, which incurs various types of errors as well as requiring a lot of time and money to conduct. In particular, the bus means indicators calculated using transportation card data were analyzed to compensate for the shortcomings of the existing operational status survey methods that rely entirely on site surveys. The city bus index calculated by using the transportation card data involves quantitative operation status data related to the user, and this results in the advantage of being able to conduct a complete survey without any data loss in the data collection process. We took the transportation card data from the entire city bus network of Ulsan Metropolitan City on Wednesday April 3, 2019. The data included information about passenger numbers/types, bus types, bus stops, branches, bus operators, transfer information, and so on. From the data analysis, it was found that a total of 234,477 people used the city bus on the one day, of whom 88.6% were adults and 11.4% were students. In addition, the stop with the most passengers boarding and alighting was Industrial Tower (10,861 people), A total of 20,909 passengers got on and off during the peak evening period of 5 PM to 7 PM, and 13,903 passengers got on and off the No. 401 bus route. In addition, the top 26 routes in terms of the highest number of passengers occupied 50% of the total passengers, and the top five bus companies carried more than 70% of passengers, while 62.46% of the total routes carried less than 500 passengers per day. Overall, it can be said that this study has great significance in that it confirmed the possibility of replacing the existing survey method by analyzing city bus use by using transportation card data for Ulsan Metropolitan City. However, due to limitations in the collection of available data, analysis was performed only on one matched data, attempts to analyze time series data were not made, and the scope of analysis was limited because of not considering a methodology for efficiently analyzing large amounts of real-time data.

• Korean Journal of Agricultural and Forest Meteorology
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• v.22 no.4
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• pp.327-339
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• 2020

Transpiration is the movement of water into the atmosphere through leaf stomata of plant, and it accounts for more than half of evapotranspiration from the land surface. The measurements of transpiration could be conducted in various ways including eddy covariance and water balance method etc. However, the transpiration measurements of individual trees are necessary to quantify and compare the water use of each species and individual component within stands. For the measurement of the transpiration by individual tree, the thermometric methods such as heat dissipation and heat pulse methods are widely used. However, it is difficult and labor consuming to maintain the transpiration measurements of individual trees in a wide range area and especially for long-term experiment. Therefore, the sharing of sapflow data through database should be useful to promote the studies on transpiration and water balance for large spatial scale. In this paper, we present sap flow database, which have Granier type sap flux data from 18 Korean pine (Pinus koraiensis) since 2011 and 16 (Quercus aliena) since 2013 in Mt.Taehwa Seoul National University forest and 18 needle fir (Abies holophylla), seven (Quercus serrata), three (Carpinus laxiflora and C. cordata each since 2013 in Gwangneung. In addition, the database includes the sapling transpiration of nine species (Prunus sargentii, Larix kaempferii, Quercus accutisima, Pinus densiflora, Fraxinus rhynchophylla, Chamecypans obtuse, P. koraiensis, Betulla platyphylla, A. holophylla, Pinus thunbergii), which were measured using heat pulse method since 2018. We believe this is the first database to share the sapflux data in Rep. of Korea, and we wish our database to be used by other researchers and contribute a variety of researches in this field.