• Title/Summary/Keyword: land structure

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Investigation of Durability of Electric Power Concrete Structures Exposed to Reclaimed Marine Land (해안매립지에 위치한 전력구 콘크리트 구조물의 내구성 조사)

  • Kim, Seong-Soo;Park, Kwang-Pil;Nam, Ba-Reum;Yoo, Ju-Hwan
    • Proceedings of the Korea Concrete Institute Conference
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    • 2006.05b
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    • pp.597-600
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    • 2006
  • In Marine Land underground reinforced concrete structures, such as electric box power structure, water and chloride ion penetrated into concrete through the cracks of concrete and its permeable property, cause the corrosion of reinforcing steel bar, which accelerates the expansive cracks and deterioration of concrete. The purpose of this paper is to evaluate on deterioration of durability concrete through instrumental analysis such as schmidt hammer and carbonation, chloride content. Under the reclaimed marine land, the main cause of deterioration of concrete structures is the steel corrosion due to the penetration of chlorides and the deterioration of outer concrete itself by chemical attack.

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Deforestation and Forest land Use in Côte d'Ivoire: Policy and Fiscal Instruments

  • Djezou, Wadjamsse Beaudelaire
    • Journal of Forest and Environmental Science
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    • v.32 no.1
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    • pp.55-67
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    • 2016
  • This paper investigated policies that drive the sustainable management of Ivorian forest which disappear at an annual rate of 250000 hectares. Based on an inter-temporal model for optimum allocation of forest land to three competing uses, the article found that sustainability depends on the incentive structure, of which forest taxes and fees are a key, though obviously not the sole, component. The study proposed to increase the area fee level by accounting for environmental externalities generated by forest harvesters and farmers. The paper showed that the area fee is a decreasing function of the forest natural rate of regeneration and the reconversion rate of agricultural surfaces. Finally, at the given forest natural rate of regeneration and the reconversion rate of agricultural surfaces, the model argued that the area fee need to be progressive (arithmetic progression) in the context of ecological equilibrium break while it should remain constant in normal situation.

Numerical Analysis of Meso-Scale Circulation with Inclusion of a Layer of Vegetation over Ulsan Area (식생의 영향을 고려한 울산지역의 중규모 지역기상장에 관한 연구)

  • Lee, Seong-Dae
    • Journal of Korea Water Resources Association
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    • v.30 no.2
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    • pp.119-129
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    • 1997
  • A three-dimensional numerical model for the simulation of meso-scale local circulation is developed and it is applied to the land and sea breezes which take place around Ulsan. The surface temperature and moisture on the land are determined by means of the surface heat budget with a layer of vegetation considered. The vertical diffusion coefficients of momentum, heat and specific humidity at the surface layer are obtained by the lever-2 model of the turbulence closure proposed by Yamada (1982). This model proved to be effective in simulating the structure of the land and sea breezes around Ulsan.

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Histochemical and Ultrastructural Studies on the Salivary Gland of a Land Snail, Nesiohelix samarangae (동양달팽이 (Nesiohelix samarangae) 타액선의 조직화학적 및 미세구조적 연구)

  • Lee, Yong-Seok;Kang, Bo-Ra;Shin, Hui-Jin;Jeong, Kye-Heon
    • The Korean Journal of Malacology
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    • v.20 no.1
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    • pp.7-16
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    • 2004
  • Histochemical and ultrastructural studies on the salivary gland and salivary duct of a land snail Nesiohelix samarangae were conducted to observe structural characteristics and function. The salivary gland consisted of one type of epithelial cell, one type of supporting cell, and six types of gland cells. Four out of six gland cell types were histochemically identified on these secretions. The one secreted acid mucopolysaccharide and the other three secreted neutral mucopolysaccharide. The salivary duct epithelium had only one type of columnar cell with microvilli on its luminal surface. The basal protoplasmic membranes of the epithelial cells were deeply infolded so many times all along the cell bases.

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A Study on the Land Price Characteristicsin Urban Railway Station's Surrounding Zones of Gwangju City, Korea (도시철도 개통에 따른 광주시 역세권 지가의 특성에 관한 연구)

  • Kim, Yu-Ho
    • The Journal of the Korea institute of electronic communication sciences
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    • v.7 no.1
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    • pp.171-180
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    • 2012
  • This study shows that access to urban railway station affects the development of railway station's surrounding zone (RSSZ). For instance, the value of the property in RSSZ is likely to rise on the basis of the before and after the opening of a urban railway. Urban railway system is believed as an important solution to resolve worsening transport problems in metropolitan city. Also, the opening of a urban railway line is expected to affect the change of urban spatial structure, and to have more influence on land price of RSSZ.

Study on the Limit Slenderness of a Double Outrigger System (이중 아웃리거 구조 시스템의 한계 세장비에 대한 연구)

  • Yang, Jae-Kwang;Kang, Ho-Geun;Park, Sung-soo
    • Journal of the Architectural Institute of Korea Structure & Construction
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    • v.34 no.3
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    • pp.11-18
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    • 2018
  • Due to the recent overpopulation of urban cities, land shortage and soaring land prices have caused an increase in the demand for high-rise buildings. To build buildings on a limited land, the size of the building is important. Displacement control by horizontal loads in a skyscraper is critical to securing stability and usability of structures. Several systems have been proposed for efficient horizontal displacement control, and so far the study continues. Among them, the Outrigger System is a representative of the typical horizontal load resistance system. Although studies have been conducted so far to locate the optimal position of the outrigger, studies of the slenderness ratio of the buildings are still insufficient. Based on the Outrigger-Optimized Position equation, this study induces the calculation of the displacement of the outrigger installation building according to the slenderness ratio.

Urban Thermo-profiles and Community Structure of Quercus mongolica Forests along an Urban-rural Land Use Gradient: Implications for Management and Restoration of Urban Ecosystems

  • Cho, Yong-Chan;Cho, Hyun-Je;Lee, Chang-Seok
    • Journal of Ecology and Environment
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    • v.32 no.3
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    • pp.167-176
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    • 2009
  • Land cover changes associated with urbanization have driven climate change and pollution, which alter properties of ecosystems at local, regional, and continental scales. Thus, the relationships among urban ecological variables such as community composition, structure, health, soil and functioning need to be better understood to restore and improve urban ecosystems. In this study, we discuss urban ecosystem management and research from a futuristic perspective based on analyses of vegetation structure, composition, and successional trends, as well as the chemical properties of soils and the distribution of heat along an urban-rural gradient. Urban thermo-profile analysis using satellite images showed an obvious mitigating effect of vegetation on the Seoul heat island. Community attributes of Quercus mongolica stands reflected the effects of urbanization, such as pronounced increases in disturbance-related and pollution-tolerant species, such as Styrax japonica and Sorbus alnifolia. Retrogressive successional trends were detected in urban sites relative to those in rural sites. Changes in the urban climate and biotic environment have the potential to significantly influence the practice and outcomes of ecological management, restoration and forecasting because of the associated changes in future bio-physical settings. Thus, for management (i.e., creation and restoration) of urban green spaces, forward-thinking perspectives supported by historical information are necessary.

Construction of 3D Earth Optical Model for Earth Remote Sensing (Amon-Ra) Instrument at L1 Halo Orbit

  • Ryu, Dong-Ok;Seong, Se-Hyun;Hong, Jin-Suk;Kim, Sug-Whan
    • Bulletin of the Korean Space Science Society
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    • 2011.04a
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    • pp.30.1-30.1
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    • 2011
  • We present construction of 3D Earth optical Model for in-orbit performance prediction of L1 halo orbiting earth remote sensing instrument; the Albedo Monitor and Radiometer (Amon-Ra) using Integrated Ray Tracing (IRT) computational technique. The 3 components are defined in IRT; 1) Sun model, 2) Earth system model (Atmosphere, Land and Ocean), 3)Amon-Ra Instrument model. In this report, constructed sun model has Lambertian scattering hemisphere structure. The atmosphere is composed of 16 distributed structures and each optical model includes scatter model with both reflecting and transmitting direction respond to 5 deg. intervals of azimuth and zenith angles. Land structure model uses coastline and 5 kinds of vegetation distribution data structure, and its non-Lambertian scattering is defined with the semi-empirical "parametric kernel method" used for MODIS (NASA) missions. The ocean model includes sea ice cap with the sea ice area data from NOAA, and sea water optical model which is considering non-Lambertian sun-glint scattering. The IRT computation demonstrate that the designed Amon-Ra optical system satisfies the imaging and radiometric performance requirement. The technical details of the 3D Earth Model, IRT model construction and its computation results are presented together with future-works.

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Structural Analysis of Underground Parking Garage Under Vehicle Load (지하주차장 차량하중에 따른 구조체의 영향분석)

  • Kim, Young-Jin;Lee, Bum-Sick;Choi, Dong-Sub;Oh, Hyo-Keon;Kang, Chang-Bum
    • Journal of the Korean Society for Advanced Composite Structures
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    • v.4 no.4
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    • pp.22-29
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    • 2013
  • Accumulation of more than 20,000,000 vehicles since the establishment of the quality of life and economic development needs several parking lots and cause crack problem in Korea. Related structures in large cities due to the lack of parking garage attached to secure underground parking structures are actively being built, and the basement parking lot will continue to increase more stories and the trend is expected to be larger. But so far, construction of the underground parking structure is related to a number of problems, including cracks in the structure. Therefore, in this study, repair, reinforcement and a few non-economic losses in the current design criteria are presented. The review of the structure used to current design criteria is to minimize crack and maximize usability.

Vegetation Structure and Management Planning of Mountain Type Urban Green Space in Inchon, Korea : a case study of land area (인천광역시 산지형 도시녹지의 식생구조 및 관리계획: 육지지역을 중심으로)

  • Cho, Woo
    • Journal of the Korean Institute of Landscape Architecture
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    • v.26 no.2
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    • pp.15-27
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    • 1998
  • The purposes of this study were to investigate vegetation structure and present management planning of mountain type green space using the green space changes during the 20 years, actual vegetation, and plant community structure in land area of Inchon, Korea. The actual vegetation area in survey sites was consisted of Quercus acutissima community, Robinia pseudoacacia forest, Pinus rigida forest, Q. mongolica-Pinus rigida community, P. rigida-Q. mongolica community, Q. monogolica community and so on. According to the classification by TWINSPAN, 61 survey plots were divided into 9 groups; Q. mongolica-Alnus japonica-R. pseudoacacia-P. densiflora, R. pseudoacacia-Styrax japonica, P. rigida-R. pseudoacacia-Q. mongolica, R. pseudoacacia-P. rigida-Q. mongolica-A. hirusta, Q. mongolica-P. thunbergii, and prunus sargentii-Zelkova serrata community. From this result, ecological succession trend of vegetation seems to be change from artificial result, ecological succession trend of vegetation seems to be change from artificial planting forest to native plant community which was dominated by Quercus spp.. This study area need to manage for the increase of biodiversity through the restoration of naturalness by ecological management of artificial planting forest and ecological planting of injured green space.

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