• Title/Summary/Keyword: Excavations

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Development of Laboratory hazard discovery and management techniques (연구실 유해인자 발굴 및 관리기법 개발에 관한 연구)

  • Lee, Hyung-Kyu;Lee, In-Bok;Sin, Young-Te;Moon, Jin-Young;Lee, Ik-Mo
    • Journal of the Korea Safety Management & Science
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    • v.18 no.4
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    • pp.81-90
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    • 2016
  • Research and development activities have been actively conducted at universities, research institutions and research laboratories which belong to corporations. Because of blooming research and development activities in various fields, safety accidents in the laboratories happen consistently. The government office established Act on the establishment of safe laboratory environment to decrease safety accident rates and make environment of laboratories better, and it is effective slowly. However, in the case of laboratory safety management of the laboratory where various research and development activities are carried out. So it is difficult to closely monitor them. Even though safety inspections and periodic inspections is regularly conducted, these are focused on facilities and environment. According to a study of Dea-deok science town safety council, accidents in laboratories of 73% have arisen out of careless actions. Therefore, it is important for researchers to know to potential harmful factors in research. there is necessary to make a system to prevent laboratory accidents. The purpose of this study is that the researchers discovered potential hazard factors in laboratories. For that, foreign laboratory safety management systems has applied to domestic laboratories. Four laboratories in targeted institution has been selected to apply the appropriate personal protection equipments, job safety assessment and standard operating procedures. And I found the limitations of the process according to the excavations harmful factors in the research process. To overcome these limitations, Suggest a laboratory safety management system. This study discovered current laboratory safety system limitations and provides alternatives so that effective safety management can be achieved.

Study on Distortion Compensation of Underwater Archaeological Images Acquired through a Fisheye Lens and Practical Suggestions for Underwater Photography - A Case of Taean Mado Shipwreck No. 1 and No. 2 -

  • Jung, Young-Hwa;Kim, Gyuho;Yoo, Woo Sik
    • Journal of Conservation Science
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    • v.37 no.4
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    • pp.312-321
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    • 2021
  • Underwater archaeology relies heavily on photography and video image recording during surveillances and excavations like ordinary archaeological studies on land. All underwater images suffer poor image quality and distortions due to poor visibility, low contrast and blur, caused by differences in refractive indices of water and air, properties of selected lenses and shapes of viewports. In the Yellow Sea (between mainland China and the Korean peninsula), the visibility underwater is far less than 1 m, typically in the range of 30 cm to 50 cm, on even a clear day, due to very high turbidity. For photographing 1 m x 1 m grids underwater, a very wide view angle (180°) fisheye lens with an 8 mm focal length is intentionally used despite unwanted severe barrel-shaped image distortion, even with a dome port camera housing. It is very difficult to map wide underwater archaeological excavation sites by combining severely distorted images. Development of practical compensation methods for distorted underwater images acquired through the fisheye lens is strongly desired. In this study, the source of image distortion in underwater photography is investigated. We have identified the source of image distortion as the mismatching, in optical axis and focal points, between dome port housing and fisheye lens. A practical image distortion compensation method, using customized image processing software, was explored and verified using archived underwater excavation images for effectiveness in underwater archaeological applications. To minimize unusable area due to severe distortion after distortion compensation, practical underwater photography guidelines are suggested.

Derivation of Flexural Rigidity Formula for Two-row Overlap Pile Wall (2열 겹침주열말뚝의 휨 강성 산정식 유도)

  • Choi, Wonhyuk;Kim, Bumjoo
    • Journal of the Korean Geosynthetics Society
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    • v.17 no.4
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    • pp.109-118
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    • 2018
  • Two-row overlap pile wall, currently under development for use in deep excavations, is a novel retaining structure designed to perform itself as a cutoff wall as well as a high-stiffness wall by constructing four overlapping piles arranged in zigzag manner at a time using a tetra-axis auger. This wall has a relatively complex cross-section, compared with other types of pile wall, which would make it difficult to determine design parameters related to cross-section. In this study, a flexural rigidity equation has been derived by analyzing both theoretically and statistically various wall cross-sections with different pile diameters and overlap lengths. The flexural rigidity equation was found to show the maximum error rate of 3%.

Water-induced changes in mechanical parameters of soil-rock mixture and their effect on talus slope stability

  • Xing, Haofeng;Liu, Liangliang;Luo, Yong
    • Geomechanics and Engineering
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    • v.18 no.4
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    • pp.353-362
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    • 2019
  • Soil-rock mixture (S-RM) is an inhomogeneous geomaterial that is widely encountered in nature. The mechanical and physical properties of S-RM are important factors contributing towards different deformation characteristics and unstable modes of the talus slope. In this paper, the equivalent substitution method was employed for the preparation of S-RM test samples, and large-scale triaxial laboratory tests were conducted to investigate their mechanical parameters by varying the water content and confining pressure. Additionally, a simplified geological model based on the finite element method was established to compare the stability of talus slopes with different strength parameters and in different excavation and support processes. The results showed that the S-RM samples exhibit slight strain softening and strain hardening under low and high water content, respectively. The water content of S-RM also had an effect on decreasing strength parameters, with the decrease in magnitude of the cohesive force and internal friction angle being mainly influenced by the low and high water content, respectively. The stability of talus slope decreased with a decrease in the cohesion force and internal friction angle, thereby creating a new shallow slip surface. Since the excavation of toe of the slope for road construction can easily cause a landslide, anti-slide piles can be used to effectively improve the slope stability, especially for shallow excavations. But the efficacy of anti-slide piles gradually decreases with increasing water content. This paper can act as a reference for the selection of strength parameters of S-RM and provide an analysis of the instability of the talus slope.

Survey and Archaeological Research on the Shàngdu(上都) Site in Yuán(元) Ruins (원상도(元上都)의 조사와 건축유적의 고고학 연구)

  • Wei, Jian
    • Korean Journal of Heritage: History & Science
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    • v.45 no.3
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    • pp.28-59
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    • 2012
  • The $Sh{\grave{a}}ngdu$ site in the Yuan Dynasty of China, a capital city located in the northern steppe area characterised by the nomadic life, has received great attentions from a number of travellers, historians and archaeologists. Several famous European travellers described vividly the city structure and civil life of $Sh{\grave{a}}ngdu$ from the Yuan Dynasty onwards. Since the begging of the modern era, a number of foreign expeditionists and historians explored $Sh{\grave{a}}ngdu$ and published research reports. From the 20th century, mainly Chinese and Japanese historians and archaeologists carried out the relatively detailed historical researches and archaeological surveys to the $Sh{\grave{a}}ngdu$ site; and published books, articles and excavation reports. More detailed and scientific archaeological investigations, mappings and excavations have been conducted since 1990s. This paper aims to progress basic discussion to the city structures of the $Sh{\grave{a}}ngdu$ site based on the previously conducted researches by expeditionists, geographers and archaeologists and the full scale investigations, which have been carried out since the late 20th century.

Safety Effect Evaluation of Existing Metro Tunnel by Deep Urban Tunnelling (대심도 도심지 터널시공에 의한 기존 지하철 터널 안전영향 평가)

  • Han, Sang-Min;Lee, Dong-Hyuk;Lee, Sung-Ho
    • Journal of the Korean Geotechnical Society
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    • v.37 no.9
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    • pp.37-50
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    • 2021
  • Recently, due to the expansion of urban infrastructure using underground spaces in urban areas, many adjacent constructions and excavations have been made carried out between existing facilities, and complaints related to the stability of existing facilities due to close construction have become significant issues. In this study, it was closely reviewed for the existing metro tunnel structure in the new Dongbuk urban metro railway to determine the behavioral characteristics of tunnel structure according to adjacent tunnel construction. Also, it was analysed the evaluation of the safety zone and excavation method for metro tunnel structure. And after a detailed damage assessment, track irregularities and structural calculation by using a numerical analysis, stability of the metro tunnel structure according to nearby tunnel excavation was evaluated to be secured for safety. This study is expected to be applied as practical reference to review the evaluation of safety effects of existing tunnel structure and buildings according to adjacent construction in complex deep urban tunnelling.

The Ethnobotanical Knowledge on Sedge Plants in Korea (Cyperaceae)

  • Chung, Kyong-Sook;Kang, Shin-Ho
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2019.10a
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    • pp.20-20
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    • 2019
  • Sedge family is second largest family in the Korean flora with more than 240 taxa, following Aster family (about 300 taxa). Although high species diversity, a very limited number of taxa has been utilized for ethnobotanical usages. In the study, previous researches on Cyperaceae ethnobotanical information are documented and analyzed for future research directions on the taxa. A total number of seven taxa has been used for medicinal, food, and material purposes: Carex boottiana Hook. & Arn., Cyperus amuricus Maxim., Cyperus esculentus L., Cyperus exaltatus Retz., Cyperus rotundus L., Eleocharis kuroguwai Ohwi, and Bolboschoenus maritimus (L.) Palla. Underground parts such as tubers are used with medicinal purpose, and aboveground portions such as leaves and stems provide materials for various tools and foods for people and animals. They are all native to Korea, except C. esculentus, which is introduced from Mediterranean areas for anti-erosion materials. The ethnobotanical value of C. esculentus has been well recognized from ancient times, for example, starch grains in USA (excavations at the Mashantucket Pequot Reservation) and Tiger nut milk (Horchata de chufa in Spain). Among material sources, C. exaltatus has a long history in the Korean peninsula from Three Kingdoms of Korea (57 BC~668 AD). C. rotundus is distributed widely in Asia, Africa, Europe, and America, and utilized for medicines, food, and materials. In addition, Eleocharis kuroguwai is only one taxon utilized for ethnobotanical uses among fifteen Eleocharis Korean native species. The number of species with ethnobotanical uses is small in sedge family, but the family has long been utilized accompanying long human history. Cyperus papyrus L., the source of papyrus paper (Egypt in the Nile Delta), is also a member of sedge family. Sedge family has contributed to human societies in various aspects but, the cultural, botanical, ecological values of family members have been underestimated.

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Study on the restoration of Soswaewon Garden's Goam-Jeongsa and Boohwondang buildings (소쇄원 고암정사와 부훤당의 복원적 고찰)

  • Cheon, Deuk-youm;Choi, Jung-mee;Kim, Dyeon-jin
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.34 no.4
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    • pp.103-111
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    • 2018
  • The Soswaewon Garden, which was constructed by Yang San-Bo around 1520, is a private traditional garden in Korea. Soswaewon Garden has long been and still is the focus of continuous research. However, relatively few studies have been conducted on the restoration of buildings that were lost in the past. The Goam-Jeongsa and Boohwondang buildings, which were lost in 1597 during the Japanese invasion, were restored in 1614 and depicted in a picture of Soswaewon Garden in 1755. However, they eventually disappeared and no longer exist in the present. Therefore, the restoration of these two buildings is considered an urgent task. This research aims to search for the original location of these buildings and estimate their size and shape in terms of physical space. Several years ago, an estimation of the building site was carried out, providing a stepping stone on this matter. This can be studied through "Soswaewon's 48 quatrains with five Chinese characters in each line," "Soswaewon-sasil," and "Soswaewon's drawing." Some parts of the shape of Soswaewon also appear in the "Yuseoseokrok," which is helpful. Thus, in this research, information on the Goam-Jeongsa and Boowondang buildings appearing in research results and literature to date are collectively analyzed. The location and architectural features of both buildings are identified by focusing on excavations. Also, for the purpose of restoration planning, base data on the location, size, and shape of both buildings are presented. In line with this process, a valid restoration plan is presented by analyzing the abovementioned historical research materials and comparing empirical data, such as excavation results.

A Case Study on Reinforcement Method by Excavation Adjacent to the Subway Tunnel using Numerical Analysis (수치해석을 통한 지하철 구조물 인접 굴착에 따른 보강공법 적용사례연구)

  • Byun, Yo-Seph;Jung, Kyoung-Sik;Chun, Byung-Sik
    • Journal of the Korean GEO-environmental Society
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    • v.12 no.9
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    • pp.5-11
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    • 2011
  • Recently, large and deep excavations are increasing. The damage of adjacent structures due to excavation has steadily increased with increasing construction demand. Especially in urban development and poor conditions, the excavation adjacent to the subway structures has caused a lot of problems. This paper was reviewed that the underground excavation and reinforcement of the status process through a case study on the field. And stability analysis through the case study evaluates applicability for reasonable reinforcement method by numerical analysis. As a result, the strata distribution condition of all 16 sites consisted of landfill from the top and distributed in the order of deposits, weathered soils, weak rock from the bottom. Also, when proceeding the excavation adjacent to structures, the location of site and layer conditions have highly effect on the results of the construction. Therefore, this study was applied reinforcement method to protect damage by excavation. Displacement and settlement were within allowable criterion and hence, stability of structure was analyzed as safe.

A Study on the Location of Goryeo GangdoPalace (고려 강도궁궐 위치 연구)

  • Bin, Kyung-Min
    • Journal of architectural history
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    • v.30 no.3
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    • pp.55-66
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    • 2021
  • The purpose of this study is to review the research on Gangbang Palace and to presume the location of the palace through the study of feng shui. when the Mongols invaded, Ganghwado was the capital, moved from Gaegyeong and it was maintained for 39 years. At that time, the palace construction followed the palace of Gaegyeong, and the names such as Gujeong毬庭, Palace, and Sasa寺社 were the same as those of Gaegyeong. However, despite several archaeological excavations at Goryeo Palace Site, Historic Site No. 133, no actual remains of the Goryeo period were found. After the negative opinions on the current Goryeo Palace site became public, there have been several previous studies on the estimation of the location of the Goryeo Palace Site, and although there have been achievements, the location of the Goryeo Palace is still not confirmed. The key to presuming the location of the GangdoPalace江都宮闕 is first, whether the palace was located in the south of Songaksan, and second, at what point it was located in the south of Songaksan. As to whether the palace was located in the south of Songaksan, it was presumed that the Chiso治所 of Ganghwabu was located in Gukhwari, referring to the record in 『Shinjeungdongguknyeojiseungnam新增東國輿地勝覽』 that Goryeosan, a guardian mountain鎭山, was 'five ri west of Bu府西五里'. Accordingly, the location of the palace of 'Budongsimni 府東十里' in the old literature was estimated to be south of Songaksan Mountain. Also, the location of the palace on the south side of Songaksan was approached from a feng shui theory. Three places for the palace to be located are presumed to be 'Ganghwa Girls' High School', 'Seonggwang Church', or 'Above the Ganghwa-gun library', and the central axis of the palace is estimated to be 'Above the Ganghwa-gun library' where the corridor-type building relics were found among them, and the other two areas were presumed to be other buildings within the palace.