• Journal of Information Processing Systems
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• v.10 no.3
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• pp.384-394
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• 2014

The femtocell overlaid cellular network (FOCN) has been used to enhance the capacity of existing cellular systems. To obtain the desired system performance, both cross-tier interference and co-tier interference in an FOCN need to be managed. This paper proposes an interference management scheme that adaptively constructs a femtocell cluster, which is a group of femtocell base stations that share the same frequency band. The performance evaluation shows that the proposed scheme can enhance the performance of the macrocell-tier and maintain a greater signal to interference-plus-noise ratio than the outage level can for about 99% of femtocell users.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2003.10a
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• pp.152-152
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• 2003

The majority of the SKYBIO will be used in the treatment of water in food processing plants, swimming pools and cooling towers, in the manufacture fabric softeners in Australia. Most will eventually be released into domestic sewage system as a consequence of product use. The SKYBIO is not readily biodegradable (0% over 28 days), and is expected to have a low partition coefficient and high water solubility (285 g/L), all indicating that the material would be mobile in both aquatic and terrestrial compartment. The PEC/PNEC ratio for the aquatic environment is 56. This value is significantly greater than 1, indicating an immediate concern to the aquatic compartment. However as a consequence of it's cationic character, the SKYBIO will be expected to associate to negatively charged organic matter in soil and sediment.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.5A
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• pp.702-708
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• 2000

In this paper, we designed one-dimensional VLSI array with optimal pipeline period for high speed processing fractal image compression. The algorithm is derived which is suitable for VLSI array from axed block partition algorithm. Also the algorithm satisfies high quality of image and high compression-ratio. The designed VLSI array has optimal pipeline relied because the required processing time of PEs is distributed as same as possible. As this result, we can improve the processing speed up to about 3 times. The number of input/output pins can be reduced by sharing the input/output and arithmetic unit of the domain blocks and the range blocks.

• Journal of Computing Science and Engineering
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• v.1 no.2
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• pp.195-210
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• 2007

Dwarf is a highly compressed structure, which compresses the cube by eliminating the semantic redundancies while computing a data cube. Although it has high compression ratio, Dwarf is slower in querying and more difficult in updating due to its structure characteristics. We all know that the original intention of data cube is to speed up the query performance, so we propose two novel clustering methods for query optimization: the recursion clustering method which clusters the nodes in a recursive manner to speed up point queries and the hierarchical clustering method which clusters the nodes of the same dimension to speed up range queries. To facilitate the implementation, we design a partition strategy and a logical clustering mechanism. Experimental results show our methods can effectively improve the query performance on data cubes, and the recursion clustering method is suitable for both point queries and range queries.

• Korean Journal of Plant Resources
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• v.11 no.3
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• pp.326-334
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• 1998

Vascular cambium in 16 species of Salicaceae is nonstoried in all of them and is made up of fusiform and ray initials. The growth of cambial girth occurred by pseudotransverse division of fusiform initials and subsequent apical intrusive growth of daughter initials. The measurements of fusiform initials in tangerntial sections have revealed that the average length varies from 252.2-437.1${\mu}{\textrm}{m}$ in investigated species, with the maximum being in Populus euramericana and the minimum in Salix purprea var. Multinervis. The length of fusiform initials depends on the length of the tapering end wall , therefore, the longer the length of the tapering end wall, therefore, the longer the length of the taperding end wall, the longer the length of fusiform initials. Ray initials have their own size, magnitude, and frequency of occrrence in each species. The relative proportion of ray initials fall about 15.0-24.5% in Salicaceae. Shrubby species of Salix have a lower ratio of ray initials than the species which possess wider trunks. New ray initials are originated from cut off the side or the end of fusiform initials and central partition of a fusiform initials.

• Journal of the Korean Institute of Telematics and Electronics
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• v.23 no.4
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• pp.429-438
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• 1986

In this paper we have designed and implemented a real-time, full-duplex SBC (sub-band coding) codec at 16kbps using a high speed digital signal processor, NEC 7720. The SBC codec employs a QMF(quadrature mirror filter) filter bank based on the tree structures of two-band analysis-synthesis pairs to partition speech signal into 4 octabe bands. Computer simulation has been done to investigate the effect of fixed-point computation of the NEC 7720. Three different performance measures, the conventional signal-to-noise ratio, the informal listening test, and an LPC(linear predictive coding)distance measure, have been used in this simulation. The necessary parameters have been optimized through the simulation. The developed hardware and software have been tested in real-time operation using a hardware emulator.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.17 no.4
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• pp.291-298
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• 1984

The extracted hagfish (Eptatretus burgeri) flesh lipid was separated into following fractions by column chromatography on Bio-beads SX-2 and Sephadex LH-20 prior to gab chromatographic analysis of their fatty acid compositions: polar lipid, triglyceride and free fatty acid. The major fatty acids of total lipid and triglyceride in hagfish were $C_{16:0},\;C_{16:1},\;and\;C_{18:1}$. The ratio of $C_{18:0}/C_{18:1}$ in the total lipid and triglyceride of hagfish was 0.1. The polar lipid of the hagfish muscle was mainly composed of phosphatidyl choline ($65.5\%$) and phosphatidyl ethanolamine ($28.0\%$). The triglyceride obtained was fractionated into four fractions by HPLC on the basis of partition numbers. Both the fatty acid composition and triglyceride composition on the basis of the total carbon number in the acyl chains of the triglyceride were analysed by the GLC. From the information obtained on triglyceride compositions based on the total carbon number by GLC and the partition number by HPLC and fatty acid composition by GLC, the combination of fatty acid in each triglycerides was estimated. A computer was used for estimation of the fatty acid combination in the triglyceride because hagfish lipid triglyceride was composed of various kinds of fatty acids. Fortyfour kinds of triglyceride were estimated. The major triglycerides in hagfish flesh lipid were found to those of ($1{\times}C_{16:0},\;2{\times}C_{18:1};\;13.5\%$), ($1{\times}C_{16:0},\;1{\times}C_{18:0},\;1{\times}C_{18:1};\;7.2\%$), ($1{\times}C_{16:1},\;2{\times}C_{18:1};\;5.4\%$), ($2{\times}C_{16:0},\;1{\times}C_{22:5};\;5.2\%$), ($1{\times}C_{14:0},\;2{\times}C_{18:1};\;4.5\%$), ($2{\times}C_{18:1},\;1{\times}C_{22:5};\;3.6\%$), ($1{\times}C_{14:0},\;1{\times}C_{18:0},\;1{\times}C_{18:1};\;2.7\%$) and ($1{\times}C_{14:0},\;1{\times}C_{16:0},\;1{\times}C_{18:2};\;2.2\%$).

• Korean Chemical Engineering Research
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• v.53 no.6
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• pp.695-702
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• 2015

Liquid-liquid extraction (LLE) using various solvents was studied for recovery of acetic acid from a synthetic ethanol fermentation broth. The microbial fermentation of sugars presented in hydrolyzate gives rise to acetic acid as a byproduct. In order to obtain pure ethanol for use as a biofuel, fermentation broth should be subjected to acetic acid removal step and the recovered acetic acid can be put to industrial use. Herein, batch LLE experiments were carried out at $25^{\circ}C$ using a synthetic fermentation broth comprising $20.0g\;l^{-1}$ acetic acid and $5.0g\;l^{-1}$ ethanol. Ethyl acetate (EtOAc), tri-n-octylphosphine oxide (TOPO), tri-n-octylamine (TOA), and tri-n-alkylphosphine oxide (TAPO) were utilized as solvents, and the extraction potential of each solvent was evaluated by varying the organic phase-to-aqueous phase ratios as 0.2, 0.5, 1.0, 2.0, and 4.0. The highest acetic acid extraction yield was achieved with TAPO; however, the lowest ethanol-to-acetic acid extraction ratio was obtained using TOPO. In a single-stage batch extraction, 97.0 % and 92.4 % of acetic acid could be extracted using TAPO and TOPO when the ratio of organic-to-aqueous phases is 4:1 respectively. A higher solvent-to-feed ratio resulted in an increase in the ethanol-to-acetic acid ratio, which decreased both acetic acid purity and acetic acid extraction yield.

• Journal of Korea Water Resources Association
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• v.30 no.2
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• pp.177-191
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• 1997

The influences of the space allocation of design rainfall and partition of the subbasin on the characteristics of urban storm runoff was investigated for the 6 drainage basins by applying SWMM model. It show the deviation of -54.68∼18.77% in the peak discharge when we applied the composed JUFF quantiles to the two zones which are divided by upper and lower region of the basin. Then it is compared with the value for the case of using uniform rainfall distribution all over the drainage. Therefore, it would be helpful to decrease the flood risk when we adopt the space distribution of the design rainfall. The effects of the partitioning the drainage on the computing result shows various responses because of the surface characteristics of the each basin such as slope, imperviousness ratio, buy we can get closer result to the measured value as we make the subbasin detailed. If we use the concept of the skewness and area ratio when we determine the width of subbasin, we can improve the computed result even with fewer number of subbasins. We expect reasonable results which close into the measured results in the range of relative error, 25%, when we divide the basin into more than 3 subbasins and the total urban drainage area is less than 10$\textrm{km}^2$.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.24 no.3
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• pp.259-266
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• 2011

The transient vibration test and synchronized human excitation is performed for low-rise concrete buildings and their identified natural frequency, damping ratio, and mode shape are compared. Form the identified dynamic parameters, it was found that the damping ratio obtained through the synchronized human excitation test is greater than those obtained from the transient vibration test. However, the mode shapes of the first mode are not significantly different regardless of the test method. Further, the stiffness of the interior brick partition considerably affect the stiffness of the entire building such that the first natural mode of rectangular shaped building occurred in the longitudinal direction rather than transverse direction.