• Coupled systems mechanics
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• v.5 no.2
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• pp.157-190
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• 2016

This paper deals with frequency analysis of Euler-Bernoulli beams carrying an arbitrary number of Kelvin-Voigt viscoelastic dampers, subjected to harmonic loads. Multiple external/internal dampers occurring at the same position along the beam axis, modeling external damping devices and internal damping due to damage or imperfect connections, are considered. The challenge is to handle simultaneous discontinuities of the response, in particular bending-moment/rotation discontinuities at the location of external/internal rotational dampers, shear-force/deflection discontinuities at the location of external/internal translational dampers. Following a generalized function approach, the paper will show that exact closed-form expressions of the frequency response under point/polynomial loads can readily be derived, for any number of dampers. Also, the exact dynamic stiffness matrix and load vector of the beam will be built in a closed analytical form, to be used in a standard assemblage procedure for exact frequency response analysis of frames.

• ALGAE
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• v.23 no.3
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• pp.177-186
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• 2008

The present paper consists of 42 taxa belonging to 7 genera of desmids (green algae) collected from two districts of Garhwal region of Uttarakhand (Western Himalayas). The district Haridwar is located 29° 55’to 29° 59’N latitude and 68° 5’to 68° 30’E longitude covering about 2360 km2 area and Dehradun district is situated between 77° 34’to 78° 18’E longitude and 29° 58’to 30° 58’N latitude. Seven genera of desmids are (with number of taxa in parenthesis): Closterium Nitzsch. (9), Cosmarium Corda ex Ralfs (25), Euastrum Ehr. (2), Spondylosium Breb. (1), Micrasterias Ag. (1), Staurastrum Meyen (3), Arthrodesmus Ehr. (1). All these taxa constitute new records for the area. The algal localities are relatively cleaner than those of majority of urban areas. A rich assemblage of desmids shows that water bodies of these hilly areas are still undisturbed and need protection for preservation of algal biodiversity.

• Mycobiology
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• v.35 no.4
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• pp.186-190
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• 2007

This study was conducted to investigate the effects of foliar endophytic fungi and arbuscular mycorrhizal fungi (AMF) on plant community structure in experimental microcosms containing an assemblage of five species of plants (Oenothera odorata, Plantago asiatica, Trifolium repens, Isodon japonicas and Aster yomena). Leaves of Sasa borealis, Potentilia fragarioides, and Viola mandshurica were collected in Chungbuk, Korea. Endophytic fungi were isolated from the surface sterilized leaves and identified to species level using molecular and morphological techniques. Four isolates of the endophytic fungi were inoculated to the leaves of host plants in the microcosms. Also, three species of AMF spores were extracted from pure cultures and the mixture of the three species inoculated to the roots of the plants. After four months of growth in a green house, effects of both symbiotic fungi on plant species diversity, community composition and productivity were examined. The plant species diversity showed significant differences with inoculation of the symbiotic fungi. Results indicate that AMF significantly affect plant productivity and plant community structure.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.05a
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• pp.101-102
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• 2017

This study was carried out as basic study to apply to construction site the HPC method which is being developed. The construction cost of HPC method was analyzed in comparison with conventional method (half slab method). With regard to research method, it was decided that data on construction work carried out by half slab method was analyzed. According to the results of study, in case of being applied to the construction work using a divided column, the number of columns was decreased. So, it was shown that member production cost, and transport and assemblage cost reduced. In case of being applied to construction work using an undivided column, the analysis showed that there was little difference in construction cost. Therefore, the analysis showed that, if HPC construction method was applied to large structure using a large column, the construction cost was reduced to some extent in comparison with conventional half slab method.

• Journal of the Korean Society for Advanced Composite Structures
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• v.2 no.1
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• pp.8-14
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• 2011

This study aims at grasping the structural performances of primary anchor assemblage through a nonlinear finite element analysis. Primary anchor unit may be used as one of the connection devices between ALC panel curtain-wall and RC slab or main frame of a building. From the analytical results structural characteristics such as yield strength, initial stiffness and maximum strength are obtained and fully discussed.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.4
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• pp.429-436
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• 2017

The seasonal and interannual variations in fish assemblages in the coastal waters off Gijang were examined with an otter trawl from 2015 to 2016. A total of 59 fish species was collected during the study period. The dominant species were Caelorinchus multispinulosus, Clupea pallasii pallasii and Chelidonichthys spinosus. Seasonal changes in fish assemblages appeared to be distinct in the study area. The fish assemblages in summer and autumn were clearly distinguishable from those in other seasons, and the largest numbers of species and individuals were captured in winter and summer, respectively. Because fish assemblages are closely related to changes in water temperature, long-term changes in water temperature can have a significant impact on the productivity of offshore fisheries by changing fish species composition, habitat migration, and growth rate of fish.

• Journal of the korean society of oceanography
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• v.31 no.1
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• pp.7-17
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• 1996

The species composition and distribution patterns of the subtidal benthic faunal assemblage in Sokmo and Yomha Channels and Kyonggi Bay were studied in spring and fall of 1989 and correlated to some environmental variables: temperature, salinity and substrate type. For both seasons, a total of 7,779 organisms were counted belonging to 244 species. Of these, 3,647 organisms in 185 species were counted for spring (March 1989) and 4,132 in 189 species for fall (September 1989). The oyster, Cressostrea gigas and the tellinidean bivalve, Moerella rutilla were the two most abundant species in the spring, constituting 17.22%and 6.47% of the total abundance respectively. While in the fall, the barnacle, Balanus reticulatus and macrura, Ogyrides orientalis dominated comprising 13.72% and 6.87 % of the total number of individuals. Community structure analysis revealed good correlations with the variations of salinity in Yomha and Sokmo Channels and sedimentary facies in Kyonggi Bay, Korea.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2005.11b
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• pp.329-337
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• 2005

Synroc which comprises hollandite-rich ($Ba_{1-x}Cs_{2x}\;(Al_yTi_{2-y})\;Ti_{6}O_{16},\;75wt\%$), perovskite ($Ca_{1-x}Sr_xTiO_3,\;15wt\%$) and rutile ($TiO_2,\;10wt\%$) is devised for the immobilization of Sr/Cs (1:3, wt$\%$) separated from HLW liquid. Especially, hollandite-rich Synroc with different contents of Al element is fabricated, and its mineral phase assemblage and microstructure are determined by using XRD and SEM/EDS. The durability test is carried out by using MCC-1 method, leachate is analyzed by using ICP/MS and ICP/ AES. The results indicate that hollandite-rich Synroc variants is a suitable host for Immobilization of Sr/Cs separated from HLW liquid.

• Economic and Environmental Geology
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• v.21 no.2
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• pp.139-148
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• 1988

The altered volcanic rocks, ranging from tuffaceous to andesitic rocks are widely distributed around the "caldera" area in the southeastern part of Kyeongsang province. The volcanic activity and tectonic movement are assumed to be followed by the hydrothermal activities in the area. From the mineral assemblage the type of alteration can be divided into two types; propylitic and argillic. The average concentration of gold in hydrothermally altered rocks is somewhat lower (about 20 ppb) than that of fresh rocks (45-25 ppb), but for Ag, vice versa. During the hydrothermal process, the concentration of the trace elements Ag, Hg, Co, As, Hf, Sc, Si, Al increased, and that of Na, Rb, K, Au, Mg, Ca etc. decreased. The high anomalous contents of silver for altered rocks range from 4-7 ppm and 1-3 ppm for relatively fresh rocks.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2001.10a
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• pp.393-400
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• 2001

A simple numerical modelling technique is proposed for estimating the shear stress distribution in beams of framed tube structures with multiple internal tubes. The structures are analysed using a continuum approach in which each tube is individually modelled by a tube beam that accounts for the flexural and shear deformations, as well as the shear lag effects. The method idealises the discrete tubes-in-tube structures as an assemblage of equivalent multiple beams, each composed of orthotropic plate panels. The numerical analysis of shear stress is based on the elastic theory in conjunction with the minimum potential energy principle. By simplifying assumptions regarding the form of strain distributions in external and internal tubes, the shear stress distributions are expressed in terms of a series of linear functions of the second moments of area of the structures and the corresponding geometric and material properties, as well as the applied loads. The simplicity and accuracy of the proposed method are demonstrated through the solutions of three numerical examples.