• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.4
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• pp.529-541
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• 2015

We examined the species composition and community structure of demersal fish in the middle and southern coastal waters of the East Sea of Korea by surveying a commercial Danish seine fishery from 2010 to 2013. We considered the waters north of $37^{\circ}N$ as middle and those south of $37^{\circ}N$ as southern waters. A total of 79 demersal fish species belonging to 18 families were collected. Of these, 59 species (77.6%) inhabited only the East Sea as opposed to the West and South Seas of Korea, and most were resident species. The species and biomass were similar between the two portions of the study area. The sandfish Arctoscopus japonicus (78.0%) and the blackfin flounder Glyptocephalus stelleri (65.1%) were the most common species and accounted for the most biomass in the middle and southern waters, respectively. Fish were most abundant at shallow depths (50-100 m) in the middle portion of the East Sea. Using a cluster analysis, we divided the species composition and community structure at the sampling stations into three groups: middle portion (group A), deep area of the southern portion (group B), and shallow areas of the southern portion (group C). A. japonicas and G. stelleri were dominant in groups A and B, while G. stelleri and Clupea pallasii were dominant in group C.

• The Korean Journal of Ceramics
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• v.6 no.4
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• pp.380-384
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• 2000

Crystal structure of $Ba_5-5X$Y$_10/3$Nb$_10$O$_30$ was tried to determine by Rietveld analysis using powder X-ray diffraction data. This compound has tetragonal tungsten bronze (TTB) structure with general formula, (Al)$_2$(A2)$_4$(B1)$_2$(B2)$_8$(O1)$_8$(O2)$_8$(O3)$_4$(O4)$_2$(O5)$_4$(O6)$_4$. However, it was difficult to determine the distribution of Ba and Y in Al and A2 sites by the analysis only. Combination of Rietveld analysis and site potentials calculation as well as lattice energy calculations helped to determine the distribution. As the result, it was clarified that $Ba^2+$ cations occupy A2 (pentagonal tunnel site) and $Y^3+$ cations occupy Al (cubic site). The distribution of cations at each site coincides with the distribution estimated by the difference of ionic radii. This supports the formation condition of TTB which was proposed in our previous report. $Ba_5-5X$Y$_10X/3$Nb$_10$O$_30$ shows ferroelectric characteristics. In this compound, remanent polarization decreases slightly with the composition X. On the other hand, the result of crystal structure determination reveals that atomic positions along c-axis for A1, A2, B1 and B2 cations are also decreased with the composition X. This would suggest that the dependence of remanent polarization on composition X is derived by the dependence of atomic coordinates on composition X.

• Journal of the Korean housing association
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• v.10 no.2
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• pp.175-183
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• 1999

This study aims at modeling the compositional method in the architectural space and shape. The composition of space is composed of the position and the area in space. Therefore these elements are established to the functional program applied at the behavioral data. The element of spatial structure is position and scale in space, and the composition of spatial shape is developed repitionally to the combination of build-up method. The functional program is being expertised and the scale in building being lager, the importance of functional program is increased. Applied at data of the functional program at spatial structure, the process is developed to the method of combination. The purpose of this study is approached at the degree of application in modeling on the compositional method in architectural space and shape, which is a fundamental aspect on the quantitative analysis of architectural space.

• The Korean Journal of Ecology
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• v.20 no.1
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• pp.15-25
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• 1997

The deciduous shrubs, Lindera sericea belonging to family Lauracea are distributed in Mt. Chogye and Mudeung locally. To estimate the community structure of this shrub, the relationship between the floristic composition and environmental factors of 20 sites in Mt. Chogye were investigated. L. sericea community distributed at the hum양 zone of altitude 305-480 m in ES and NE slope of $15~30^{\circ}$. The floristic composition of this communities consisted of 17-32 species varied with sites. Sasa borealis, Sapium japonicum, and Quercus serrata were the constant species over 90%. The forest vegetation was classified as Sasa borealis-Lindera sericea community, and the Sasa borealis-Meliosma oldhamii, and Sasa borealis-Callicarpa japonica were as subunit community. Acidity, organic matter content, inorganic phophate, potassium, calcium, magnesium, cation exchange capacity and conductivity were determined as environmental factors. Diameter of stem at ground surface and stem, distribution area and growth property of this plant were investigated, and this plant was presumed to be a relic endemic species.

• Journal of Educational Research in Mathematics
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• v.12 no.1
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• pp.17-27
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• 2002

To solve the addition word problems provides young children the chance to learn about and exercise in problem solving. This paper focuses on two aspects to be considered in addition word problems: the homogeneity of objects and the variety of contexts. The homogeneity of objects involved in addition word problems has to be kept in the following reasons: concept of unit, effectiveness of information, prevention of inappropriate variety, inconsistency of mathematics with real world, continuity between elementary and secondary mathematics. And for the variety of contexts, the additive structure proposed by G. Vergnaud, can be considered: composition, transformation, relation of comparison, composition of two transformations, composition of two relations, transformation of a relation. According to this structure, some examples, which contain homogeneous objects, were extracted from the elementary school mathematics textbooks.

• Journal of Surface Science and Engineering
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• v.25 no.5
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• pp.223-233
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• 1992

(Ti, Al)N films were deposited on 304 stainless steel by D.C. magnetron sputtering using Al target and Ti plate. The properties of (Ti, Al)N films such as composition, microhardness, grain size, crystal structure were investigated. The chemical composition of (Ti, Al)N films was similar to the sputter area ratio of titanium to aluminum target by means of EDS and AES survey. The higher bias voltage to substrate and the smaller input of N2 gas showedthe increased microhardness and the finer grain size of the films. The results obtained from this study show, it is belived, that the (Ti, Al)N film by D.C.magne-tron sputtering is promising in the wear resistance use.

• Journal of the Korean Magnetics Society
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• v.5 no.5
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• pp.720-725
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• 1995

Bi-substituted gadolinium iron garnet films were deposited on GGG(111) and NGG (111) substrates by irradiating KrF excimer laser onto targets having compositions of $Bi_{x}Gd_{3-x}Fe_{5}O_{12}$ ($2.0{\leq}x{\leq}3.0$) under substrate temperature of $580~620^{\circ}C$. Analysis on structure, composition and angle of Faraday rotation, ${\theta}_{F}$, were carried out. The composition, the structure and the magneto-optical properties of the obtained films were found to be strongly dependent both on the compositions of the targets and on the pressure of oxygen. Before annealing in air, all films showed ${\theta}_{F}{\geq}0$ at ${\lambda}=6328{\AA}$, while several films showed ${\theta}_{F}{\leq}0$ after the annealing. The highest value of Bi-substitution up to x = 1.76 with uniform composition was obtained.

• Plant Resources
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• v.4 no.1
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• pp.59-64
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• 2001

This study was conducted to clarify the floristic composition and to investigate the landscape structure of habitats of Aconitum pseudo-leave var. erectum. A. pseudo-leave is designated an endemic plant in Korea. Floristic compositions of habitats were mainly composed of Quercus mongolica community. Other elements in this composition were Weigela subsessilis, Corylus sieboldiana and Cornus contioversa. Landscape ecological structure of habitats were defined by soils of mesic, loamy skeletal, slope of more than 60$^{\circ}$, sixty percent of woody coverage at 460-520m above the sea level and 25m away from drainage. Distribution patterns of A. pseudo-leave var. erectum plants in Taejon were presented on the 1km X 1km grid map.

• Plant Resources
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• v.7 no.1
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• pp.22-28
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• 2004

The purposes of this study were to clarify of floristic composition and the landscape structure on the habitats of three Thalictrum plants, which were distributed in Daejeon, Korea. Floristic composition of habitats was organized by living in flatten open space needed a lot of sunlight and humidity. Landscape ecological structure of habitats was defined by soils of loamy skeletal mesic, slope between 25 to 30$^{\circ}$ Vegetation rating was 75 percent of woody coverage at less than 450 m above the sea levels, respectively. Distribution patterns of Thalictrum plants in Daejeon were presented on the 1 km X 1 km grid map.

• Fisheries and Aquatic Sciences
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• v.26 no.7
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• pp.423-436
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• 2023

The objectives of this review were to synthesize the community structure of phytoplankton and the role of atelomix in the phytoplankton dynamics in Ethiopian highland lakes. Changes in a lake's physical structure, light dynamics, and availability of nutrients are closely associated with phytoplankton ecology, and phytoplankton assemblages provide insight into phytoplank- ton responses to these environmental changes. Based on the available information, a total of 173 species of phytoplankton are grouped under seven classes, Chlorophyceae (80 taxa), Bacillariophyceae (55 taxa), Cyanophyceae (24 taxa), Dinophyceae (6 taxa), Eugleonophyceae (6 taxa), Xanthophyceae (1 taxon), and Cryptophyceae (1 taxon) were recorded in five different tropical Ethiopian highland lakes. Chlorophyceae and Bacillariophyceae dominated in terms of species composition. Partial atelomixis, seasonality, and low nutrient concentrations seem to be the main drivers in structuring phytoplankton composition and abun-dances in Ethiopian highland lakes, characterized by a high diversity of atelomix-dependent benthic diatoms and desmids. Thus, this review will help understand the role of atelomix and nutrient availability in the phytoplankton composition and biomass of tropical highland lakes of Ethiopia.