• The Korean Journal of Ecology
• /
• v.17 no.2
• /
• pp.185-201
• /
• 1994

The Quercus mongolica forest vegetation of Mt. Myongji was classified into two communities including four subunit communities and one typical subunit community by the Z-M method as follows: Acer pseudo-sieboldianum-Quercus mongolica community group Quercus mongolica - Isodon excisus community Quercus mongolica - Styrax obassia community Quercus mongolica - Lespedeza bicolor subunit coummunity Quercus mongolica - Aconitum longecassidatum subunit community Quercus mongolica - Rhododendrom schlippenbachii subunit community Quercus mongolica - Cornus controversa subunit community Quercus mongolica - Styrax obassia typical subunit community Acer pseudo-sieboldianum - Quercus mongolica community group was distributed over the upper region of the altitude 400m, and the differential species in the community were Carex siderosticata, Sephanandra incisa, Tripterygium regelii, and Fraxinus rhynchophylla. The vegetation patterns for the slope and azimuth showed that the highest importance value for Quercus mongolica forest was observed on the broad subxeric area, and for Carpinus cordata and Acer pseudo-sieboldianum on the wet site, for Acer mono, Styrax obassia, Fraxinus rhynchophylla and Symplocos chinensis for. pilosa on the xeric site. The best habitat condition for Quercus mongolica was found at a subxeric site at the altitude of 700-900m on southern slope and that for Acer pseudo-sieboldianum at the 700-1100m on northern slope.

• International Journal of High-Rise Buildings
• /
• v.3 no.3
• /
• pp.215-221
• /
• 2014

Ultra-high strength concrete and high tensile steel are becoming very attractive materials for high-rise buildings because of the need to reduce member size and structural self-weight. However, limited test data and design guidelines are available to support the applications of high strength materials for building constructions. This paper presents significant findings from comprehensive experimental investigations on the behaviour of tubular columns in-filled with ultra-high strength concrete at ambient and elevated temperatures. A series of tests was conducted to investigate the basic mechanical properties of the high strength materials, and structural behaviour of stub columns under concentric compression, beams under moment and slender beam-columns under concentric and eccentric compression. High tensile steel with yield strength up to 780 MPa and ultra-high strength concrete with compressive cylinder strength up to 180 MPa were used to construct the test specimens. The test results were compared with the predictions using a modified Eurocode 4 approach. In addition, more than 2000 test data samples collected from literature on concrete filled steel tubes with normal and high strength materials were also analysed to formulate the design guide for implementation in practice.

• The Plant Pathology Journal
• /
• v.29 no.3
• /
• pp.323-329
• /
• 2013

The stationary-phase sigma factor, RpoS, influences the expression of factors important in survival of Pseudomonas chlororaphis O6 in the rhizosphere. A partial proteomic profile of a rpoS mutant in P. chlororaphis O6 was conducted to identify proteins under RpoS regulation. Five of 14 differentially regulated proteins had unknown roles. Changes in levels of proteins in P. chlororaphis O6 rpoS mutant were associated with iron metabolism, and protection against oxidative stress. The P. chlororaphis O6 rpoS mutant showed increased production of a pyoverdine-like siderophore, indole acetic acid, and altered isozyme patterns for peroxidase, catalase and superoxide dismutase. Consequently, sensitivity to hydrogen peroxide exposure increased in the P. chlororaphis O6 rpoS mutant, compared with the wild type. Taken together, RpoS exerted regulatory control over factors important for the habitat of P. chlororaphis O6 in soil and on root surfaces. The properties of several of the proteins in the RpoS regulon are currently unknown.

• Journal of Soil and Groundwater Environment
• /
• v.20 no.3
• /
• pp.15-24
• /
• 2015

The soil ecosystem is a complex system performing particularly complicated and varied functions, such as providing a habitat for organisms, acting as a medium for plant cultivation and growth, and functioning as a buffer against external materials in the environment. To assess whether these important functions of the soil ecosystem are executed appropriately, the concept of soil ecosystem health has been introduced, which is defined as the ability to perform the specific functions of the soil ecosystem. Understanding soil properties and soil indicators related to soil functions is essential to assess the soil health. In this study, systems, the indicators, and evaluation factors for assessing soil ecosystem health employed in a number of countries were investigated and discussed. In particular, it is necessary to introduce a technique for the evaluation of soil ecosystem health in Korea and to develop techniques and indicators appropriate to the soil ecosystem and status in Korea.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2003.05a
• /
• pp.10-16
• /
• 2003

Natural resource plants have been useful and helpful materials for human to against diseases and Prevention since ancient Egyptian and Roman times. However, according to recent survey, its habitat and indigenous are continuously decreased and almost extinct some valuable species, as Adonis vernalis, Digitalis lanata etc., especially in Eastern Europe and east Asian countries due to radical political and social reforms. ESCOP and FAO have already initiated to protect the endangered species for conservation, protection and propagation technology but it is not easy tasks without global concerning. Most natural resource plants have volatile components in essential oils and its consumption and demanding is increased every year, which contained certain compounds have no side effects and good properties for biological activities. Essential oils of natural resource plants are also well known for medical purposes, such as Central Nervous System (CNS, linalool), anticancer (d-limonene, perillyl alcohol, etc.), microbial and fungicidal activities (menthol, borneol, etc). Essential oil also used for natural therapy to prevent and increase immune systems instead of chemical synthesis drugs. With this, researchers of natural resource plants are ultimately faced to develop and optimal technology for increasing the Korean farmer's income by high added-value herbal products in present and future.

• International Journal of High-Rise Buildings
• /
• v.6 no.1
• /
• pp.83-89
• /
• 2017

Due to the time-dependent properties of materials, structures, and loads, accurate time-dependent effects analysis and precise construction controls are very significant for rational analysis and design and saving project cost. Elevation control is an important part of the time-dependent construction control in supertall structures. Since supertall structures have numerous floors, heavy loads, long construction times, demanding processes, and are typically located in the soft coastal soil areas, both the time-dependent features of superstructure and settlement are very obvious. By using the time-dependent coupling effect analysis method, this paper compares Shanghai Tower's vertical deformation calculation and elevation control scheme, considering foundation differential settlement. The results show that the foundation differential settlement cannot be ignored in vertical deformation calculations and elevation control for supertall structures. The impact of foundation differential settlement for elevation compensation and pre-adjustment length can be divided into direct and indirect effects. Meanwhile, in the engineering practice of elevation control for supertall structures, it is recommended to adopt the multi-level elevation control method with relative elevation control and design elevation control, without considering the overall settlement in the construction process.

• International Journal of High-Rise Buildings
• /
• v.6 no.1
• /
• pp.11-19
• /
• 2017

High-rise buildings move during construction due to time-dependent material properties of concrete (creep and shrinkage), construction sequences, and structural shapes. The building movements, including vertical and horizontal displacements, result from the sum of axial and lateral deformation of vertical members at each level. In addition to the vertical shortenings, the lateral movement induced by differential shortening can have adverse effects on the construction tolerance and serviceability of non-structural elements such as elevators and curtain walls. In this study a construction stage analysis method is developed to predict lateral movement induced by shortening, including the effect of creep and shrinkage. The algorithm of construction stage analysis is combined with the FE analysis program. It is then applied to predict lateral movement of a 58-story reinforced concrete building that was constructed in Kuala Lumpur, Malaysia. Gravity induced lateral movement of this building is predicted by the construction stage analysis. A field three-dimensional laser scanning survey is carried out to verify the prediction results, and satisfactory agreement is obtained.

• International Journal of High-Rise Buildings
• /
• v.2 no.3
• /
• pp.213-228
• /
• 2013

Tall buildings have been traditionally designed to be symmetric rectangular, triangular or circular in plan, in order to avoid excessive seismic-induced torsional vibrations due to eccentricity, especially in seismic-prone regions like Japan. However, recent tall building design has been released from the spell of compulsory symmetric shape design, and free-style design is increasing. This is mainly due to architects' and structural designers' challenging demands for novel and unconventional expressions. Another important aspect is that rather complicated sectional shapes are basically good with regard to aerodynamic properties for crosswind excitations, which are a key issue in tall-building wind-resistant design. A series of wind tunnel experiments and numerical simulation have been carried out to determine aerodynamic forces and wind pressures acting on tall building models with various configurations: corner cut, setbacks, helical and so on. Dynamic wind-induced response analyses of these models have also been conducted. The results of these experiments have led to comprehensive understanding of the aerodynamic characteristics of tall buildings with various configurations.

• The Korean Journal of Ecology
• /
• v.21 no.1
• /
• pp.47-63
• /
• 1998

In order to compare species-specific calcium metabolism, we collected 127 species belonging to 40 different families grown on various habitats including saline, limestone, wetland during the 1996 vegetation period, and analyzed their inorganic ion contents. Plants investigated were divided into 5 groups according to their physiological properties: 1) Chenopodiaceae, Aizoaceae, Caryophyllaceae, Portulacaceae and Phytolaccaceae of Centrospermales and Polygonaceae (Polygonales had a little water-soluble $Ca^{2+}$ but contained high contents of insoluble $Ca^{2+}$ particularly as Ca-oxalate (Chenopodiaceae type), 2) Some plant species such as Rosaceae produced oxalate in amounts insufficient to precipitate all incoming $Ca^{2+}$ and thus contained a surplus of dissolved $Ca^{2+}$ (Rosaceae type), 3) The contents of water-soluble $Ca^{2+}$ in plant species of Crassulaceae. Plantaginaceae, Asclepiadaceae, and Zygophyllaceae were equal to or greater than those of K ($K/Ca{\leq}1$; Crassulaceae type), and 4) K/Ca ratios of Compositae were significantly fluctuated depending on species and soil $Ca^{2+}$ level of their habitats (Compositae type). 5) Certain monocots (Gramineae, Cyperaceae, Juncaceae), in contrast to the dicotyledonous plant families mentioned above, showed a very distinct type of calcium metabolism, that is, the K/Ca ratios of 8~10 were maintained indifferently in the species and their habitat types (Graminae type). These results plants within the same taxon have similar physiological aspects as weel as morphological attributes. To understand calcium metabolism of certain plant species, therefore, it is desirable to approach on the basis of physiological concept (calciotroph or calciophobe) rather than the ecological one (calcicole or calcifuge).

• International Journal of High-Rise Buildings
• /
• v.8 no.3
• /
• pp.211-220
• /
• 2019

Three cases of supertall connected structures are presented and each of them represents a quite style. The first case is a strong-connected structure. The coupling function of towers and connector contributes a lot to the structural stiffness and stability. Its special construction scheme had great impact on the construction quality and the structural safety, and must be accurately considered. For the second case which is a weak-connected structure, the influences of different connecting modes to the structural dynamic characteristic were explained. Then the combined bearings were proposed to achieve the design presume. In the third case which represents the multi-supported structures, the structural distinctive mechanical properties were discussed. For the structural state during construction process is quite different from that in final service condition, two construction procedures were simulated to get an optimal one. Although there are great challenges to designers, the advantages of the supertall connected buildings are obvious. Further work is needed in this area to adapt to the development of future cities.