• Title/Summary/Keyword: 산지연구

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Research on the ancient iron technology of Jungwon, the center of iron industry (제철산업의 중심 중원에서 고대 제철기술을 탐구하다)

  • Do, Eui Chul;Lee, Eun Woo;Seok, Je Seop;Jang, Min Seong
    • Korean Journal of Heritage: History & Science
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    • v.48 no.1
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    • pp.148-165
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    • 2015
  • Iron was one of the most influential factors for formation and development of ancient countries. The diffusion of ironware had increased agricultural productivity and brought about military technical revolution. Needless to say, the rise and fall of the countries depended on the possession of stable iron production. Raw materials and fuels are the key factors for mass production of iron and a transportation route is essential to supply the goods. Jungwon area satisfies the three factors. There are many iron manufacture sites such as Jincheon Seokjang-ri Gusan-ri, and Chunju Chilgeum-dong Tangeumdae earthen ramparts in the Jungwon area. In order to study the ancient iron manufacture technique, reconstitution experiment was carried out using restored furnace which was made based on the Jincheon Seokjang-ri B-23 furnace. Some notable results were identified with the experiment as in the followings. Firstly, a roasting process has a connection with the decrease of hardness of the iron ore. Secondly, melting of the blast pipe as well as the formation of product within the furnace had a crucial effect on the cessation of the experiment. Thirdly, reduced iron in various locations within the furnace prove that there was enough reducing environment during the working. Not only melting point but also properties of iron can vary depending on the carbon contents. For the reason, formation of approximate environment in which iron can react to the chalcoal is the most important factor in terms of iron manufacture.

Research of private landscape architecture of the Tang Era in ancient China -based on excavated excellent articles and a book <洛陽名園記> called Nakyangmyungwonki- (중국 고대 당대(唐代) 민간 조경[사가원림(私家圓林)] 연구 - 출토된 명기(明器)와 낙양명원기를 중심으로 -)

  • Park, Kyung-Ja
    • Korean Journal of Heritage: History & Science
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    • v.38
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    • pp.285-303
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    • 2005
  • Through the excavated excellent articles of the Tang era, we have considered the building techniques and styles of a square pavilion, an octagonal pavilion, a miniature hill, a pond, etc., could read building techniques of the scenic structures on ancient literatures including records and additionally about their poetical life at that time and inquired into the arrangement, structure, building techniques, etc. of a miniature hill, a pond, a pavilion, a flowerplant, etc., on Nakyangmyungwonki. Thus, under the research on the private landscape architecture, especially the nobility gardening, around excavated excellent articles and literatures, 'A miniature hill(假山) and a pond for landscaping views formed the center of a garden, and additionally a pavilion was built and flowerplants were set. The miniature hill of laying stones and having a carven, steeping, stratifying, looking like dyed green and birds' singing among hills and eating water on the lakeshore${\ldots}$' was expressed. The pond of digging in the ground and conducting water had its water system developed. There were several kinds of pavilions such as 廳, 堂, 館, 亭, 臺, 樓, 閣, 榭, etc. As examples of landscaping plants, there were a bamboo, a lotus flower, a peony, aromatic trees a pine, a korean spindle tree, a big cone pine, an empress tree, a wild walnut, a peach, a plum, a Japanese apricot tree, an apricot tree, a chrysanthemum, arrowroot vines, etc. Thus, the garden of the Tang era, abundant, diverse and excellent, enjoyed the prime of the period of prosperity. Due to cultural exchange, it is supposed that the period of united Shilla of the same age would meet with the period of prosperity in the developmental history of Korea landscape, based on the nobility garden system '4 different dwelling-houses every season on a record "四節游宅"'.

The Geology and Variations of Soil Properties on the Slow-moving Landslide in Yangbuk-myun, Gyungju-si, Gyeongsangbuk-do (경상북도 경주시 양북면 땅밀림지의 지질 및 토양물리성의 변화)

  • Park, Jae-Hyeon;Park, Seonggyun
    • Journal of Korean Society of Forest Science
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    • v.108 no.2
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    • pp.216-223
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    • 2019
  • This study was conducted to measure the changes in the geological and soil properties following slow-moving landslide events in Yangbuk-myun and Gyungju-si, Gyeongsangbuk-do, South Korea. The geological characteristics of the study site comprised black shale in the Gyeongsang nodal group formed in the Cretaceous period and quartz feldspar carcinoma in the east side with conglomerate in the Yeonil group formed in the Quaternary period. The study site exhibited the geologic characteristics of a slow-moving landslide with severely weathered rocks. The maximum collapsing depth of the slow-moving landslide was 12.0 m with colluvial deposits. The strike and joint aspects in the slope areas of the slow-moving landslides were $N46^{\circ}E$ in lower slope and $N62^{\circ}E$ in upper slope, respectively. Soil hardness of ${\leq}20cm$ deep was not measured because of the completely disturbed soil resulting from soil creeping. Soil from 25 to 90 cm deep was 1.4-4.7 times softer in the slow-moving landslide areas than in the undisturbed or natural forests. Soil bulk density was $1.24-1.29g/cm^3$ in land creep areas. Soil bulk in both areas was 1.6 times denser than that in the natural forest. The soil pore space was 51.5-53.3% in the land creep areas. The values are 1.3-1.4 times lower than those within the natural forest. Black shale areas showed the lowest coefficient of permeability (8.75 E-06 cm/s) and mesopore ratio (pF 2.7: 9.8%) compared with those resulting from other study areas.

Characteristics of the spatio-temporal distributions of water quality and phytoplankton communities in the Isa Stream systems (ISS) (이사천 수계의 수질환경과 식물플랑크톤 군집의 시·공간적 분포 특성)

  • Park, Jong Sick;Cheong, Cheong-Jo;Yoon, Yang Ho
    • Korean Journal of Environmental Biology
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    • v.39 no.3
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    • pp.273-288
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    • 2021
  • We analyzed the spatio-temporal distribution characteristics of water quality and phytoplankton communities in the Isa Stream systems (ISS) from Sangsa Lake to Suncheon Bay. Sangsa Lake showed relatively oligotrophic and mesotrophic conditions, but the freshwater and mixed brackish water zones showed more severe eutrophication than Sangsa Lake and Suncheon Bay due to the influence of industrial waste such as livestock waste. In terms of the phytoplankton community, the number of phytoplankton species was higher in freshwater and mixed brackish water zones than in Sangsa Lake and Suncheon Bay, but the cell density and Chlorophyll-a concentrations (Chl-a) were relatively high in Sanga Lake and Suncheon Bay. In particular, the mesotrophic species Fragilaria crotonensis and Asterionella formosa showed different dominance in the surface and bottom layers, and the influence of A. formosa was significant in the freshwater and mixed brackish water zones in spring and summer. However, Skeletonema costatum-ls, a eutrophic indicator species, dominated in mixed brackish water zones to seawater in autumn and winter. Thus, the severe eutrophication and rapid environmental changes in the ISS could seriously damage the coastal ecosystem in Suncheon Bay. These ecosystem changes are threatening in terms of conservation and management of the UNESCO Suncheon Biosphere Reserve and Yeoja Bay including Suncheon Bay, which recorded the first Ramsar wetland in Korea. Therefore, further research is needed to establish an in-depth management plan.

Comparison of Three Ergonomic Risk Assessment Methods (OWAS, RULA, and REB A) in Felling and Delimbing Operations (벌도 및 가지제거작업에서 세 가지 인간공학적 위험 평가기법의 비교분석)

  • Cho, Min-Jae;Jeong, Eung-Jin;Oh, Jae-Heun;Han, Sang-Kyun
    • Journal of Korean Society of Forest Science
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    • v.110 no.2
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    • pp.210-216
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    • 2021
  • Musculoskeletal disorders affect workers' safety in most industries, and forest operations are classified as a musculoskeletal burden according to the Occupational Safety and Health Act in South Korea. In particular, felling and delimbing operations are mainly conducted by manpower, and then, it is necessary to evaluate ergonomic risk assessment for safety of felling and delimbing workers. Three ergonomic risk assessment methods, such as Ovako Working posture Analysis System (OWAS), Rapid Upper Limb Assessment (RULA), and Rapid Entire Body Assessment (REBA), are available for assessing exposure to risk factors associated with timber harvesting operations. Here, three ergonomic risk assessment methods were applied to examine ergonomic risk assessments in chainsaw felling and delimbing operations. Additionally, exposure to risk factors in each method was analyzed to propose an optimal working posture in felling and delimbing operations. The risk levels of these operations were evaluated to be highest in the RULA method, followed by the OWAS and REBA methods, and most of the exposed working postures were examined with a low-risk level of two and three without requiring any immediate working posture changes. However, two significant working postures, including the bending posture of the waist and leg in felling operation and standing posture on the fallen trees in delimbing operation, were assessed as the high-risk level and needed immediate working posture changes. Low-risk work levels were examined in the squatting posture for felling operation and the straightened posture of the waist and leg for delimbing operation. Moreover, the slope in felling operation and the tree height in delimbing operation significantly affected risk level assessment of working posture. Therefore, our study supports that felling and delimbing workers must operate with low-risk working postures for safety.

Evaluation of Steep Slopes Adjacent to Multi-use Facilities in National Parks using GIS (GIS를 활용한 국립공원 다중이용시설 인접 급경사지 평가)

  • Lee, Dong Hyeok;Jun, Kye Won;Jung, Min Jin;Park, Jun Hyo
    • Journal of Korean Society of Disaster and Security
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    • v.14 no.4
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    • pp.29-36
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    • 2021
  • Recently, due to climate change, the slope is increasing, and the risk of steep slope disasters such as the occurrence of slope collapse in the east coast and Busan region in 2019 and the Gokseong landslide in 2020 is increasing. Particularly, most national parks are made up of mountainous areas, and the risk of disasters on steep slopes is increasing. As the ground of the national park is aging and the weathering and jointing of the bedrock are accelerating due to climate change, the slope collapse and rockfall are increasing, and the annual number of visitors is increasing, it is necessary to manage steep slopes adjacent to multi-use facilities with many users. In this study, dangerous steep slopes that affect multi-use facilities in national parks were analyzed using GIS and verified through field surveys. As a process for extracting steep slopes adjacent to multi-use facilities in national parks, the slope was made in DEM and slopes of 34 degrees or higher were extracted. The difference between the maximum and minimum heights of the extracted slopes was used to confirm that the slopes met the standard for steep slopes, and the analysis of the slope direction was used to confirm whether it had an effect on the multi-use facilities. After that, precision aerial images and field photos were analyzed to finally identify risks at 4 sites, and field surveys were conducted. As a result of the field survey, all 4 sites were found to be steep slopes, 3 were graded D and 1 was graded C, so it was confirmed that management was required as a risk of collapse. All steep slopes extracted through GIS were found to be dangerous, so it is judged that the extraction of steep slopes through GIS would be appropriate.

Multi-dimensional Utilization of a Railway Facility Site and the Need for Institutional Support: The Multi-dimensional Project of the Gyeongbu Line (철도시설 부지 입체적 활용 및 제도적 지원의 필요성 - 경부선 철도 입체화 사업을 대상으로 -)

  • Shin, Eun ho;Kim, Jong gu;Kang, Youn won;Keum, Yun geon;Kwon, Young soo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.42 no.6
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    • pp.879-885
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    • 2022
  • Of increasing global popularity is the multi-dimensional use and development of cities to address land use and urban issues caused by high urban density and challenging topography. In Korea, the city of Busan has a large proportion of mountainous areas, and the Gyeongbu Line that runs through the city's center has been interrupting this urban area for over 117 years. Because a lack of usable land is hindering the development of the city, introducing a multi-dimensional approach to urban development is seen as important. Accordingly, the Gyeongbu Line underground project is attempting to solve the problem of disconnection of Busan's city center and increase the amount of usable land for varied multi-dimensional use. In this study, by conducting a preference survey among those who live near the underground project sites of the Gyeongbu Line stations in Busan, the planned use of each available land arearesulting from the multi-dimensional development of railroadsand railway stations was investigated. However, in order to further the results of the survey, legal and institutional support is needed. There are limits to the multi-dimensional use of land, such as the lack of interconnection between individual laws and the lack of specific guidelines for multi-dimensional development.

Vegetation Classification and Ecological Characteristics of Black Locust (Robinia pseudoacacia L.) Plantations in Gyeongbuk Province, Korea (경북지방 아까시나무 조림지의 식생유형과 생태적 특성)

  • Jae-Soon Song;Hak-Yun Kim;Jun-Soo Kim;Seung-Hwan Oh;Hyun-Je Cho
    • Journal of Korean Society of Forest Science
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    • v.112 no.1
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    • pp.11-22
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    • 2023
  • This study was established to provide basic information necessary for ecological management to restore the naturalness of black locust (Robinia pseudoacacia L.) plantations located in the mountains of Gyeongbuk, Korea. Using vegetation data collected from 200 black locust stands, vegetation types were classified using the TWINSPAN method, the spatial arrangement status according to the environmental gradient was identified through DCA analysis, and a synoptic table of communities was prepared based on the diagnostic species determined by determining community fidelity (Φ) for each vegetation type. The vegetation types were classified into seven types, namely, Quercus mongolica-Polygonatum odoratum var. pluriflorum type, Castanea crenata-Smilax china type, Clematis apiifolia-Lonicera japonica type, Rosa multiflora-Artemisia indica type, Quercus variabilis-Lindera glauca type, Ulmus parvifolia-Celtis sinensis type, and Prunus padus-Celastrus flagellaris type. These types usually reflected differences in complex factors such as altitude, moisture regime, successional stage, and disturbance regime. The mean relative importance value of the constituent species was highest for black locust(39.7), but oaks such as Quercus variabilis, Q. serrata, Q. mongolica, Q. acutissima, and Q. aliena were also identified as important constituent species with high relative importance values, indicating their potential for successional trends. In addition, the total percent cover of constituent species by vegetation type, life form composition, species diversity index, and indicator species were compared.

Erodibility evaluation of sandy soils for sheet erosion on steep slopes (급경사면의 면상침식에 대한 사질토양의 침식성 평가)

  • Shin, Seung Sook;Park, Sang Deog;Hwang, Yoonhee
    • Journal of Korea Water Resources Association
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    • v.55 no.4
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    • pp.291-300
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    • 2022
  • Artificial disturbance in mountainous areas increases the sensitivity to erosion by exposure of the subsoil with a low loam ratio to the surface. In this study, rainfall simulations were conducted to evaluate the erodibility of sand and loamy sand in the interrill erosion by the rainfall-induced sheet flow. The mean diameters of sand and loamy sand used in the experiment were 0.936 mm and 0.611 mm, respectively, and the organic matter content was 2.0% and 4.2%, respectively. In the experimental plot, the runoff coefficient of overland flow increased 1.16 times in loamy sand rather than sand. Mean sediment yields of loamy sand and sand by sheet erosion were 3.71kg/m2/hr and 1.13kg/m2/hr respectively. The erodibility, the rate of soil erosion for rainfall erosivity factor, was 3.65 times greater in loamy sand than in sand. As the gradient of the steep slope increased from 24° to 28°, the sediment concentration and the erodibility for two soils increased by about 20%. The erodibility factor K of sandy soils for small plots was overestimated compared to the measured erodibility. This means that RUSLE can overestimate the sediment yields by sheet erosion on sandy soils.

Analysis of Stability and Behavior of Slope with Solar Power Facilities Considering Seepage of Rainfall (태양광 발전시설이 설치된 사면의 강우시 침투를 고려한 안정성 및 거동 분석)

  • Yu, Jeong-Yeon;Lee, Dong-Gun;Song, Ki-Il
    • Journal of the Korean Geotechnical Society
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    • v.39 no.7
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    • pp.57-67
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    • 2023
  • Slope failures during rainfall have been observed in mountainous areas of South Korea as a result of the presence of solar power facilities. The seepage behavior and pore pressure distribution differ from typical slopes due to the presence of impermeable solar panels, and the load imposed by the solar power structures also affects the slope behavior. This study aims to develop a method for evaluating the stability of slopes with solar power facilities and to analyze vulnerable points by considering the maximum slope displacement. To assess the slope stability and predict behavior while considering rainfall seepage, a combined seepage analysis and finite difference method numerical analysis were employed. For the selected site, various variables were assumed, including parameters related to the Soil Water Characteristic Curve, strength parameters that satisfy the Mohr-Coulomb failure criterion, soil properties, and topographic factors such as slope angle and bedrock depth. The factors with the most significant influence on the factor of safety (FOS) were identified. The presence of solar power facilities was found to affect the seepage distribution and FOS, resulting in a decreasing trend due to rainfall seepage. The maximum displacement points were concentrated near the upper (crest) and lower (toe) sections of the slope.