• Ocean and Polar Research
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• v.28 no.4
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• pp.451-457
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• 2006

Hole 1124 of ODP Leg 181 was located in the Rekohu sediment drift off eastern New Zealand in the southwest Pacific Ocean. Mean gain sizes of sortable silt were measured in two drilled cores (1124A and l124B). Chronostratigraphy of core 1124 was correlated with the well-dated nearby core S931, resulting that the age of core 1124 covers the late Pleistocene spanning about MIS (Marine Isotope Stage) 5. Mean grain size of sortable silt seemed to be relatively large during the glacial period, whereas that of the interglacial period was smaller, although several tephra layers contain some coarse-grained pyroclatic particles. The variation in mean grain size of sortable silt in Rekohu sediment drift during the late Pleistocene indicates that the intensity of Deep Western Boundary Current (DWBC) might have been enhanced during the glacial period as a result of increased production of Antarctic Bottom Water (AABW).

• Journal of Korean Society for Atmospheric Environment
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• v.1 no.1
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• pp.93-98
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• 1985

Mass size distribution of atmospheric particulates were measured using an Andersen using an Andersen sampler in urban air. The atmospheric particulates were fractionated in eight stages of an Andersen sampler operating at 28.4$\ell/min$ and collected on polyester sheets. A quartz filter was placed behind the last stage collect permeated partculates. The size distribution of atmospheric particulates were divided around 1-2 $\mu$m into two groups, coarse and fine particulates regardless of sampling times. The variation of course particulates concentration was higher than fine particulates among sampling times. Different meterorological conditions and natural phenomena brought high variation of course particulates' concentration. The rain caused removal of coarse particulates seriously and the yellow and may take part in a increase of the course particulates in spring. The average concentration of atmospheric particulates to be collected by Andersen sampler was 170.8 $\mug/m^3$ during 3 times of sampling. Among them the average concentration of atmospheric particulates which could penetrated under a bronchi and alveoli were 70.4$\mug/m^3$ and 36.6$\mug/m^3$ respectively.

• The Korean Journal of Malacology
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• v.21 no.1
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• pp.41-46
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• 2005

A series of radiotracer studies were conducted to evaluate the influence of water temperature and/or body size on the clearance rates and uptake rates of Cd, Se and Zn in the Asiatic clam, Corbicula fluminea, Asian clam Potamocorbula amurensis and Balthic clam, Macoma balthica. Uptake rates of Cd, Se and Zn were estimated simultaneously with clearance rate of clams under 3 different water temperature conditions (5, 13 and $21^{\circ}C$). The weight specific clearance and metal uptake rates of P. amurensiswere increased with temperature, however, no consistent temperature effect was observed for the other clams. The variation of uptake rates of Cd, Se and Zn along with temperature or body size in each clam species was well associated with clearance rates. The inter-species as well as the intra-species difference of metal uptake rates could be well explained by the variation of clearance rates of clam individuals.

• Journal of Korea Foundry Society
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• v.16 no.6
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• pp.565-575
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• 1996

In this study, to gain the semi-solid alloy we employed the electromagnetic rotation by a induction motor of 3-phases and 2-poles for Al-7wt%Si alloy and observed the size of primary solid particle, distribution state of primary solid particle, the degree of sphericity, and fraction of primary solid for the evaluation of its results. The size of primary solid particle increases from $98{\mu}m$ to $118{\mu}m$ as solid fraction increases from 0.2 to 0.5. The degree of sphericity increased as the solid fraction increased. Solid particles obtained from the microstructures of isothermally held sample were coarsened and the degree of sphericity was enhanced as isothermal holding time increased. However, when the sample was stirred for more than 40min, solid particles merged together and liquid phase was entrapped within the cluster of solid particles. The size of primary solid particle was not changed significantly with the variation of input voltages by 160V over which solid particles began to merge together to be a large cluster of about $170{\mu}m$ at 180V. The standard deviation and the degree of sphericity were not changed significantly with the variation of input voltage.

• Journal of Korea Foundry Society
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• v.16 no.6
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• pp.556-564
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• 1996

Variation of shape and size of solid particles and solute redistribution in Mg-9wt.%Al, AI-4.5wt.% Cu, and AI-7wt.%Si alloys were investigated when they were heated to semi-solid temperatures and held without stirring. In the case of Mg-9wt.% Al and Al-4.5wt.%Cu alloys, the polygonal shaped solid particles were agglomerated with non-uniform distribution, and there were no disappearance of the solid/solid boundary until the end of melting. But in the case of an Al-7wt.%Si alloys, two or three spherical shaped particles were coalesced or separated individually, and the coalesced particles had no solid/solid interface on the contrary to the prevous case. The maximum size of solid particles during isothermal heating at high temperature was smaller than that at lower temperature, but the time required to reach the maximum size at high temperature was shorter than that at lower temperature. The concentrations of main solute atom whose distribution coefficient is lower than 1, decreased in the primary solid particles as the liquid fraction increased, and the gradient of solute concentration was steeper in Mg-9wt.%Al alloy and Al-4.5wt.%Cu alloy than that of Al-7wt.%Si alloy.

• Applied Microscopy
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• v.43 no.2
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• pp.75-80
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• 2013

The morphological features of pollen grains collected from the broad-leaved and cylindrical-leaved Portulaca species of the Hawaiian Islands were investigated. The variation in size and surface pattern were examined using scanning electron microscopy and statistical analysis. Pollens of the Portulaca were apolar grains of monads exhibiting apertures, colpi, and relatively thin echini. Of particular interest was the differing size of pollen grains among the species studied. Pollens of the broad-leaved Portulaca were considerable in size with a length of about $73{\sim}86{\mu}m$, while the cylindrical-leaved Portulaca tended to have smaller pollen grains ranging from 50~65 in diameter. The smallest pollens were found in cultivar 2 having an average of $43{\mu}m$. The pollen was intectate, and the exine surface appeared granulous, having sculptured elements of spinules and puncta. Two types of puncta were discerned; one forming an operculum, and the other, a simple perforation. Numerous spinules and small puncta were found throughout the cylindrical-leaved Portulaca. In the present study, morphological features of pollen grains from ten Hawaiian Portulaca species, including endemic and unknown taxa, revealed the aforementioned pattern of variation. This paper aim to provide morphological information that could be of phylogenetic value within the Hawaiian Portulaca.

• Journal of the Korean Society of Food Culture
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• v.9 no.4
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• pp.401-409
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• 1994

The use of food frequency questionnaire to estimate dietary intake has become widespread in epidemiologic studies. It has been suggested that knowledge about a person's usual serving size of each food, in addition to consumption frequency, will improve the accuracy of this method. This study was performed to investigate the nutritional status and one sowing sizes of commonly consumed dishes in Korean college women. Intakes of dish or food in 156 college women were measured by 7-day weighed food records in May, 1992 and May, 1993. For each dish or food, variance in one serving size was partitioned into within-person(intraindividual) and between-person(interindividual) components. All nutrient intakes except vitamin A and vitamin C were less adequate. The major dish groups which contributed to the most daily nutrient intakes were boiled rice, bread, fruits, dairy product, and biscuit and snack groups. In more than 50% of dishes, the within-person variation was greater than between-person variation. And the variety and amount of food which was used in one dish were too variable to make standard recipe.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.8
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• pp.31-38
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• 1995

In this paper, we consider the leaky bucket parameter dimensioning problem in the presence of the cell delay variation(CDV) which arises at the customer premises network dud to the multiplexing with other traffic streams. We consider an ATM multiplexer in which a single CBR stream and several heterogeneous VBR traffic streams are multiplexed. Choosing an MMPP model for the bursty traffic streams, we derive an (MMPP+DD)/D/1/K queueing model for the evaluation of the CDV experienced by the CBR stream. We first evaluate the equilibrium queue length distribution embedded at tagged-cell arrival-time instants, based on whcih we calcuate the inter-cell time distribution and the distribution kof the number of tagged-cell departures in an arbitrary interval. Then we apply the analysis to the dimensionging problem of the leaky bucket parameters, examining how the employed traffic model affects the determination of the bucket size. Through numerical examples, we confirm that the Poisson traffic model can underestimate the bucket size, thus causing a considerable blocking probability for compliant use cells while the MMPP model can optimally design the bucket size which keeps the blocking probability under the target value.

• Journal of the Korean Society of Propulsion Engineers
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• v.12 no.5
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• pp.1-8
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• 2008

Dual-mode Phase Doppler Anemometry (DPDA) was used to scrutinize the spatial distribution characteristics of spray emanating from a small Liquid-Rocket Engine (LRE) injector. Droplet size and velocity were measured according to the variation of injection pressure along the plane normal to the spray stream and then the spray characteristic parameters such as Arithmetic Mean Diameter (AMD), Sauter Mean Diameter (SMD), number density, span of drop size distribution, and volume flux were deduced for an investigation of spray breakup characteristics. As the injection pressure increases, the number density, span, and volume flux of spray droplets become higher, whereas the AMD gets smaller.

• Transactions of Materials Processing
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• v.8 no.3
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• pp.295-295
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• 1999

In the present study, the corrosion behavior of AZ91D as-cast alloy was investigated form the viewpoint of the distribution aspect of precipitate ($Mg_{17}Al_{12}$) and the variation of Al concentration in the Mg-rich matrix. The dendrite arm spacing (DAS) of an as-cast specimen was measured as a function of degree which describes the distribution aspect of the precipitate, and the salt spray test was conducted for various grain-sired specimens fur 20 days. The dendrite arm spacing increased as the grain size increased to about 150㎛, but a constant value is indicated when the grain size exceeds that range. Although the relationship between the corrosion rate and grain size is of a nonlinear type, the linear trend between the corrosion rate and the dendrite arm spacing is maintained for the overall range of dendrite arm spacing. Since the precipitate in the as-cast alloy is discontinuously distributed, this linear relationship means that the variation of Al-solute concentration in the Mg-rich matrix has a more potent effect than the protective action of the precipitate on the corrosion behavior of an as-cast alloy.