• Journal of the Korean GEO-environmental Society
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• v.12 no.1
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• pp.13-26
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• 2011

Because the allowable current loading of buried electrical transmission cables is frequently limited by the maximum permissible temperature of the cable or of the surrounding ground, there is a need for cable backfill materials to be maintained at a low thermal resistivity during the service period. Temperatures greater than $50^{\circ}C$ to $60^{\circ}C$ may lead to breakdown of cable insulation and thermal runaway if the surrounding backfill material is unable to dissipate the heat as rapidly as it is generated. This paper describes the results of studies aimed at the development of backfill material to reduce the thermal resistivity. A large number of different additive materials were tested to determine their applicability as a substitute material. The results of Dong-rim river sand (relatively uniform) show that as water content level increases, thermal resistivity tends to decrease, whereas the thermal resistivity on dry condition is very high value($260^{\circ}C-cm/watt$). In addition, other materials(such as Jinsan granite screenings, A-2(sand and gravel mixture), E-1(rubble and granite screenings mixture) and SGFC(sand, gravel, fly-ash and cement mixture)) are well-graded materials with low thermal resistivity($100^{\circ}C-cm/watt$ when dry). Based on this research, 4 types of improved materials were suggested as the environmentally friendly backfill materials with low thermal resistivity.

• Conservation Science in Museum
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• v.26
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• pp.143-160
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• 2021

The Seoul Baekje Museum has been conducting excavations at the Ancient Tomb Complex in Seokchon-dong, Seoul (Historic Site No. 243), known to be tombs of the royal family and the ruling class during the Hanseong period of the Baekje Kingdom. In this study, gold earrings that were revealed during the excavation underwent scientific analysis and conservation treatment. Stereo microscopy, SEM, X-ray imaging, CT, and XRF were applied in the analysis, and the characteristics, internal structure, and composition of the earrings as well as their production method were investigated. The results confirmed that the main hoops of the gilt-bronze earrings were made of copper cores gilt using mercury amalgamation. The findings also revealed that the hexahedron in the middle pendant was made by connecting small rings using molten gold powder, and the pendant sphere at the end was formed by soldering two hemispheres. As for the two thin-hoop earrings, they showed similar surface compositions but were made using different methods, with one made from a copper core wrapped with a gold plate and the other made by bending a gold rod. The gold content varied depending on the item and the place of measurement, but overall the earrings showed a relatively high gold content of approximately 19 to 21K. The purity of the golden earrings and the sophisticated manufacturing techniques applied indicate the high status of the buried person and of the tomb complex in Seokchong-dong.

• Tunnel and Underground Space
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• v.31 no.6
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• pp.623-646
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• 2021

As the demand for electric power increases with acceleration of electrification at home and abroad, the needs for coal-fired electrical power plant are accordingly increased. However, these coal-fired electrical power plants induce also many environmental problems such as increase of air pollutants, increase of possibility of land contamination by reclamation of coal ash, even though these power plants have a good economical efficiency. In case of a by-product of coal-fired electrical power plants, only 70% of them are recycled and the remaining 30% of by-product are fully buried in surrounding ground. Consequently, this study deals with coal ash backfilling mechanism in abandoned mine openings for the purposes of increasing the coal ash recycling rate as well as securing the mine area stability. In order to analyze the backfill and ground reinforcement by interaction between rock mass and backfills, the copying samples of discontinuous surface with different roughnesses were produced for bond strength tests and direct shear tests. And statistical analysis was also conducted to decide the characteristics of bond and shear behavior with joint roughness and their curing day. Numerical simulations were also analyzed for examining the effect of interface behavior on ground stability.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.19 no.2
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• pp.8-19
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• 2023

Hydronic heated road pavement (HHP) systems have well studied and documented by many researchers. However, most of the systems run on asphalt, only a few are tested with concrete, and there rarely is a comparison between those two common road materials in their heating and cooling performance. The aim of this study is to investigate the thermal performance of the HHP, such as heat dissipation performance in winter season while focusing on the surface temperature of the concrete and asphalt pavement. For preliminary study a small-scale experimental system was designed and installed to evaluate the heat transfer characteristics of the HHP in the test field. The system consists of concrete and asphalt slabs made of 1 m in width, 1 m in length, and 0.25 m in height. In two slabs, circulating water piping was embedded at a depth of 0.12 m at intervals of 0.16 m. Heating performance in winter season was tested with different inlet temperatures of 25℃, 30℃, 35℃ and 40℃ during the entire measurement period. The results indicated that concrete's heating performance is better than that of asphalt, showing higher surface temperatures for the whole experiment cases. However, the surface temperature of both concrete and asphalt pavement slabs remained above 0℃ for all experimental conditions. The heat dissipation performance of concrete and asphalt pavements was analyzed, and the heat dissipation of concrete pavement was greater than that of asphalt. In addition, the higher the set temperature of the circulating water, the higher the heat dissipation. On the other hand, the concrete pavement clearly showed a decrease in heat dissipation as the circulating water set temperature decreased, but the decrease was relatively small for the asphalt pavement. Based on this experiment, it is considered that a circulating water temperature of 20℃ or less is sufficient to prevent road ice. However, this needs to be verified by further experiments or computational fluid dynamic (CFD) analysis.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.19 no.3
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• pp.1-13
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• 2023

Hydronic heated road pavement (HHP) systems have been well established and documented to provide road safety in winter season over the past two decades. However, most of the systems run on asphalt, only a few are tested with concrete, and there rarely is a comparison between those two common road materials in their performance. The aim of this study is to investigate the thermal performance of the concrete HHP systems, including surface temperature variations of experimental pavements in winter season. For preliminary study a small-scale experimental system was installed to evaluate the heat transfer characteristics of the concrete HHP in the test field. The system consists of 3 concrete slabs made of 1 m in width, 1 m in length, and 0.25 m in height. In these slabs, circulating water piping was embedded with different pipe depths of 0.08 m (Case A), 0.12 m (Case B), and 0.20 m (Case C) and same horizontal space of 0.16 m. Heating performance in winter season was tested with different inlet temperatures of 25℃, 30℃, 35℃ and 40℃ during the entire measurement period. Overall, the surface temperature of the concrete HHPs remained above 3℃ in all experimental conditions applied in this study. The results of the surface temperature measurement with respect to the pipe depth showed that Case B was the highest among the three cases. However, the closer the circulating water pipe was to the pavement surface, the greater the heat exchange rate. This results is considered that the heat is continuously accumulated inside the pavements and then the temperature inside the pavements increases, while the amount of heat dissipation decreases as the temperature difference between the inlet and outlet of circulating water decreases. In this preliminary test the applicability of the concrete HHP on road deicing was confirmed. Finally, the results can be used as a basis for studying the effects of various variables on road pavements through numerical analysis and for conducting large-scale empirical experiments.

• Bangmulgwan gwa yeongu (The National Museum of Korea Journal)
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• v.1
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• pp.198-233
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• 2024

On April 28, 2021, the bereaved family of the late Samsung Group chairman Lee Kun-Hee made a gift of 9,797 items (in 21,693 pieces) from his estate to the National Museum of Korea. Among the donated cultural heritage are 535 mirrors (in 555 pieces), which constitute the largest proportion of the metal art in the donation. This article discusses a group of mirrors from the donated collection dating to the Western Han and Samhan periods - a total of twenty-three mirrors (twenty-two from the Western Han Dynasty and one from the Samhan Period) - that are presumed to have been found together. However, there is no known case of such a large number of Western Han mirrors being discovered together, raising doubts about whether this group should be considered to have been buried all together. Furthermore, the presence of a Samhan mirror among the group suggests that this one at least must have been found together with a Western Han mirror. Additionally, considering that early Samhan mirrors have been found in the southeastern part of the Korean Peninsula, particularly in the region occupied by Jinhan Confederacy (in present-day Gyeongsangbuk-do Province), it is likely that these mirrors were also excavated somewhere in Jinhan. Also, -18 is a repurposed imitation of a jade eye cover. No similar examples have been found in Korea, China, or Japan, but there are instances of bronze mirrors being used as substitutes for jade burial ornaments that have been identified in China. The repurposing and use of Western Han mirrors as circular ornaments have been observed only in Jinhan in the southern part of the Korean Peninsula, indicating that this item was likely used in Jinhan as well. Further research and discoveries are anticipated in the future.

• Fire Science and Engineering
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• v.18 no.1
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• pp.54-66
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• 2004

In this article, we are to suggest the hazard-assessing method for the underground pipelines, and find out the pipeline-maintenance schemes of high efficiency in cost. Three kinds of methods are applied in order to refer to the approaching methods of listing the hazards for the underground pipelines: the first is RBI(Risk Based Inspection), which firstly assess the effect of the neighboring population, the dimension, thickness of pipe, and working time. It enables us to estimate quantitatively the risk exposure. The second is the scoring system which is based on the environmental factors of the buried pipelines. Last we quantify the frequency of the releases using the present THOMAS' theory. In this work, as a result of assessing the hazard of it using SPC scheme, the hazard score related to how the gas pipelines erodes indicate the numbers from 30 to 70, which means that the assessing criteria define well the relative hazards of actual pipelines. Therefore. even if one pipeline region is relatively low score, it can have the high frequency of leakage due to its longer length. The acceptable limit of the release frequency of pipeline shows 2.50E-2 to 1.00E-l/yr, from which we must take the appropriate actions to have the consequence to be less than the acceptable region. The prediction of total frequency using regression analysis shows the limit operating time of pipeline is the range of 11 to 13 years, which is well consistent with that of the actual pipeline. Concludingly, the hazard-listing scheme suggested in this research will be very effectively applied to maintaining the underground pipelines.

• Journal of forensic and investigative science
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• v.2 no.1
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• pp.32-51
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• 2007

Serial violent crimes have occurred more frequently. Additional attention is paid to relevant areas in which discussions has also increased. This study analyzed Young-cheol Yoo, serial killer case. Two of Yoo's crimes were studied for modus operandi. The cases selected were the premeditated break-in homicide of upper-class elderly people and the impulsive homicide of the Hwanghak-Dong street vendor. Crime motives, targets, times, places, means and methods were analyzed. Profiling techniques in Young-cheol Yoo cases were evaluated and the problems discovered during investigation were discussed. The followings are the findings of the analysis of the serial killer Yoo cases. Yoo exhibited a hatred toward the rich, the elderly, and women as well as a fear of diseases and death. Yoo's crime targets were the elderly residing in wealthy houses, street vendors and prostitutes. The numbers of victims were: 3 men and 5 women victims in 4 homicide cases involving the elderly residents in wealthy houses; one man in 1 street vendor homicide case 11 women in 11 prostitute homicide cases, so total 20 persons were murdered in 16 cases. The time of the crimes were between 10 am and noon in the homicide cases of the elderly and very late at night or early in the morning in the prostitute homicide cases. Means and methods facilitated include the use of a knife as a threat and a hammer made by Yoo to strike the head and face of victims. In the homicide cases involving the elderly, he attempted to disguise the crime scene as a burglary or committed arson to destroy the evidence; in the prostitute homicide cases, bodies were mutilated and buried in secret. 1) Generally each serial killer case has different characteristics, motives, and purposes; while some serial killer cases involve similar methods, others use different methods. Unlike other crimes, serial killers' characteristics and tastes are very different, so it is difficult to explain serial killings based on a specific model. It is important to accurately capture modus operandi of each serial killing and for detectives to familiarize themselves with them. The process of tracing and use of imagination which follows a serial killer's psychology and thought must be used to find out what kind of thoughts pushed the killer to commit the crime. In order to investigate and research difficult subjects such as serial killing, various methods, skills, and relevant knowledge should be studied, and institutional endeavors should go hand in hand with individual efforts.

• Korean Journal of Heritage: History & Science
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• v.47 no.1
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• pp.116-133
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• 2014

The memorial stones of Sumanotap were known to have been sequentially produced in 1719, 1773, 1874, 1653, 1874. However, after examining the chronological era (年號) and sexagesimal cycle (干支), it was found that the second and fourth memorial stones were both recorded in 1713. The reason why the records of the same period were divided into two is assumed that since the subject to repair was divided into main structure and flagpole of the temple, and it was recorded per each monk in charge and donator. On the fifth tablet of the memorial stone of Sumanotap contains all the names of monks who were in charge of repairing Sumanotap as well as the names of common donators. These people are not verified in detail though, through comparing the Buddhist names on the third memorial stone with Buddhist paintings and painting records, 12 monks were identified to be in the same names. Generally, they were active in Gangwon province, Gyeongsang province, Seoul and Gyeonggi province in the late 19th century and even after the Sumanotap repair, they took up other duties of various temples. The most notable name among the donators recorded in the memorial stones of Sumanotap was Kim Jwageun. He was the donator for the chest of gold and silver that was enshrined in the pagoda in 1874. His name was recorded with Mrs. Yang from Cheongsin and, at that time, was known just as a donator. However, actually, the donator was not Kim Jwageun but his mistress Mrs. Yang who used to be a gisaeng, called Na-hap and was from Naju. Kim Jwageun deceased in 1869 already. It is exceptional that Mrs. Yang who were the mistress of the prime minister Kim Jwageun personally participated in the Buddhist event in which king, queen, mothers of king and queen, noblewoman participated. Besides, the event of Sumanotap repair was carried out by royal family in order to celebrate the hundredth day of the prince, Sunjong and his grandfather, Heungseon Daewongun did not participate for political reason. In this situation, the domination of Mrs. Yang is considered remarkable. Meanwhile, the temples that frequently appeared among the 10 temples recorded in the memorial stone of Sumanotap are Gakhwa-sa temple in Bonghwa-gun, Gyeongsangbuk-do and Bodeok-sa temple in Yeongwolgun, Gangwon-do. Gakhwa-sa temple was a temple where the historical achievements were kept so was under the government's control. Bodeok-sa temple was the buddhist temple praying for the soul of the Danjong buried in the tomb and was managed by the government. Therefore, the face these two temples participated in the Sumanotap repair proves that Sumanotap was repaired by the supports form these two temples and the stature of Sumanotap at that time was as high as the temples where the historical achievements are store or the royal buddhist temples for praying for ancestors' souls.

• Korean Journal of Heritage: History & Science
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• v.43 no.4
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• pp.24-55
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• 2010

Jangmyeongdeung Lantern (貞陵長明燈) refers to the stone lantern placed in front of the royal tomb. It serves both symbolic and decorative purposes; symbolic because it is supposed to guard and illuminate the buried, and decorative because it is a work of sculpture that adorns the entire graveyard. The Jangmyeongdeung of Jeongneung was the earliest stone lantern to be produced during the Joseon period. Its square shape is unique among those from the early to mid-Joseon period. The three major parts of Jangmyeongdeung - the stand, the lantern, and the roof-shaped cover parts - are square in shape, differing from the octagonal shaped Jangmyeongdeung. The stand consists of three single stone blocks, the Hadaeseok(下臺石), Ganjuseok(竿柱石), and Sangdaeseok(上臺石). The Hwasaseok(火舍石), or the lantern part, is also a single stone block. Jangmyeongdeung of Jeongneung succeeds the style of those of Hyeon-neung and Jeongneung(玄正陵) of the Goryeo period and is of a better artistic quality. As the first Jangmyeongdeung lantern, it is a refined work of art that marks the foundation of the Joseon Kingdom. This paper tries to ascertain the stylistic origin of the square-shaped Jangmyeongdeung of Jeongneung and compare it with those of Buddhist temples. Consequently, similarities were found among the stone lanterns of Zen priests 'Jigong'(指空) and 'Nawong'(懶翁) in the Hweamsa Temple(檜巖寺) site from the late Goryeo period, those of Zen priest 'Muhak'(無學) of the Hweamsa Temple site, and those of national priest 'Bogak'(普覺) of Cheongnyongsa Temple(靑龍寺) from the early Joseon period. Primarily, this is because the three components(the stand, the lantern part, and the roof-shaped cover) are essentially square-shaped. Second, as the Ganjuseok(one of the components of the stand) became shorter, the stand took a more stable form. Third, the Hwasaseok(the lantern part) consists of two stone blocks joined together. Fourth, the roof-shaped cover is also in square in shape. Similarly, the Jangmyeongdeung of Jeongneung contains Buddhist elements as well. The three-bead pattern that decorates the Ganjuseok stand is an example. The three-bead pattern is one of the symbolic elements related to Tantric Buddhism. It is found on the diadems worn by Bodhisattvas from the Goryeo and early Joseon periods. The Jangmyeongdeung of Jeongneung in early Joseon directly influenced the production of the square-shaped stone lanterns used to decorate the tombs during the Joseon period. After the latter half of the 15th century, however, the octagonal-shaped Jangmyeongdeung style began to prevail. The Jangmyeongdeung of Jeongneung reflects the succession of the tradition of royal tombs from Goryeo to Joseon, the introduction of square-shaped stone lanterns to Buddhist temples, and the influence of the Buddhist philosophy of the time. It is a living testimony to various elements of each time and corresponding cultural trends.