• Journal of the Korean Society for Marine Environment & Energy
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• v.9 no.2
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• pp.85-91
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• 2006

This study deals with the flow over a flat plate with repeated roughness elements of 2-dimensional rectangular shape, which can be applied into the study on the natural geographical roughness and the turbulent flow on roughened solid surface. Part 1 of the study showed that the ratio between the spacing and the height of roughness elements plays a crucial role in developing the flow pattern near wall surface. The present study complements the turbulence characteristics, the utilization of friction velocity as well as integral parameters. Results confirmed that k-type roughness(s/H=7 or 14) is certainly a more effective means than d-type roughness (s/H=3.5) in thickening the viscous region.

• Journal of the Microelectronics and Packaging Society
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• v.18 no.4
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• pp.71-77
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• 2011

Main parameters of the screen printing were determined and the printing parameters were optimized for 0402, 0603, and 1005 chips in this study. The solder pastes used in this study were Sn-3.0Ag-0.5Cu and Sn-0.7Cu. The process parameters were stencil thickness, squeegee angle, printing speed, stencil separating speed and gap between stencil and PCB. The printing pressure was fixed at 2 $kgf/cm^2$. From ANOVA results, the stencil thickness and the squeegee angle were determined to be main parameters for the printing efficiency. The printing efficiency was optimized with varying two main parameters, the stencil thickness and the squeegee angle. The printing efficiency increased as the squeegee angle was lowered under 45o for all chips. For the 0402 and the 0603 chips, the printing efficiency increased as the stencil thickness decreased. On the other hand, for the 1005 chip, the printing efficiency increased as the stencil thickness increased.

• The Journal of the Acoustical Society of Korea
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• v.30 no.7
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• pp.390-395
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• 2011

This paper covers the studies on common voice parameters through the voice analysis of female main news anchors on weekday evening by the station, and differences of relative voices and sounds among stations. To examine voice characteristics, 6 voice parameters were analyzed and it showed anchors of each station had distinctive characteristics of voices and phonations over all fields except the speech rate, and there were also differences in sound systems. As major analysis parameters, basic pitch, tone of the 1st formant and pitch ratio, level of closeness by pitch bandwidth, type of sentence closing through average pitch position within pitch bandwidth, average speech rate, and acoustic tone analysis by energy distribution by frequency band were used. Analyzed values and results could be referred to and utilized in the criteria of phonation characteristics for domestic female news anchors.

• Korean Journal of Weed Science
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• v.10 no.2
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• pp.122-129
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• 1990

The herbicide $^{14}C$-butachlot[N-(butoxymethyl)-2-chloro-2', 6'-diethylacetanilide] labelled uniformly in benzene ring was incorporated in alginate-based granules to get controlled release properties. The influence of kaoline addition on the formulation characteristics and release profiles were evaluated under a closed dark and an opened sunlight condition. Incorporation efficiency of $^{14}C$-butachlor in alginate-kaoline matrices was over 91.8%. Formulation yield was decreased with increase of kaoline concentration. The release rate from all the granules prepared with alginate was slower than that from the commercial granule impregnated in zeolite. The release rate from the granule containing kaoline was decreased as the kaoline content was increased under both conditions. Losses of butachlor from the leacheate solution of the alginate-kaoline matrices under an opened sunlight condition was diminished by increasing the kaoline content.

• Korean Journal of Food Science and Technology
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• v.27 no.2
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• pp.246-250
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• 1995

Konjac(Amorphophallus konjac) glucomannan dispersions were prepared from konjac flour, pretreated konjac flour and purified glucomannan. Konjac glucomannan dispersions showed non-Newtonian fluid behavior without yield stress and higher shear stress at fixed shear rate than the dispersions of gum xanthan, gum carrageenan and sodium alginate. While temperature increased, shear stress at fixed shear rate of konjac glucomannan dispersion steadily decreased. The apparent viscosity of konjac glucomannan dispersion was in its maximum at pH 7, whereas decreased on the outskirts of pH 7. The change in apparent viscosity was not found up to 1% sodium chloride addition in case of konjac glucomannan dispersion. However, the apparent viscosity of konjac glucomannan dispersion decreased up to sugar addition of 10%, afterwards increased.

• Korean Journal of Weed Science
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• v.16 no.1
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• pp.64-71
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• 1996

This study was conducted to determine the physiological responses of corn plants to chlorsulfuron, CHL, (2-chloro-N-(((4-methoxy-6-methyl-1,3,5- triazin-2-yl)amino)carboxyl) benzenesulfonamide) and/or imazaquin, IMA, (2-(4,5-dihydro-4-methyl-4-(1-methyl)-5-oxo-1H-imidazol-2y1)-3-quinoline carboxylic acid). CHL inhibited the plant growth within 6h after treatment, whereas IMA inhibited the growth more slowly(i.e., 36h). CHL inhibited the cell division of the root tips rapidly, however, little effect was found with IMA treatment. Neither CHL nor IMA had effect on the cell elongation of the shoots. CHL inhibited acetolactate synthase(ALS) activity of the roots within 1h after treatment. Interaction between CHL and IMA in growth inhibition was found to be additive or synergistic with simultaneous or sequential treatment of the two herbicides, respectively. In addition, interaction between CHL and IMA in ALS inhibition was found to be additive when the two herbicides were treated simultaneously.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.31 no.4
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• pp.301-310
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• 2013

The aim of the present study is to enhance query speed of large 3D point cloud indexed in octree by parallel query using multi-cores. Especially, it is focused on developing methods of accessing multiple leaf nodes in octree concurrently to query points residing within a radius from a given coordinates. To the end, two parallel query methods are suggested using different strategies to distribute query overheads to each core: one using automatic division of 'for routines' in codes controlled by OpenMP and the other considering spatial division. Approximately 18 million 3D points gathered by a terrestrial laser scanner are indexed in octree and tested in a system with a 8-core CPU to evaluate the performances of a non-parallel and the two parallel methods. In results, the performances of the two parallel methods exceeded non-parallel one by several times and the two parallel rivals showed competing aspects confronting various query radii. Parallel query is expected to be accelerated by anticipated improvements of distribution strategies of query overhead to each core.

• Journal of Energy Engineering
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• v.2 no.1
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• pp.54-67
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• 1993

Two turbulent reaction models of the premixed CC1$_4$/CH$_4$/air mixture are successfully incorporated in a 3-dimensional computer program and is applied for Dow Chemical incinerator equipped with two main off-center burners. The first reaction model is fast chemistry model(model 1), in which chemical reaction is governed by the turbulent mixing itself. And the second one is nonequilibrium model(model 2), where the effect of the chemical kinetics due to the presence of CC1$_4$is considered by the incorporation of the burning velocity data of CC1$_4$. The second model not only shows the flame inhibition trend due to the presence CC1$_4$compound, but also predicts qualitatively the vortical stratification of the CC1$_4$concentration appeared experimentally at the kiln exit. Other comparisions of two models are made in detail.

• Korean Journal of Food Science and Technology
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• v.37 no.1
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• pp.50-54
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• 2005

Antimicrobial activities of ethanol extracts of marta rosemary (Rosemarinus officinalis L.) against Bacillus subtilis and Salmonella typhimurium were investigated under conditions similar to processing of general food materials to develop natural food preservatives. The strongest antimicrobial activities were shown against the tested organisms at pH 7. In B. subtilis, the herbal extract extended the lag phase at low concentrations, and reduced the specific growth rate during logarithmic phase at high concentrations. In S. typhimurium the herbal extract reduced the specific growth rate even at lower concentrations. These trends were obtained at low pHs of culture solution. Antimicrobial substances of herbs were efficiently extracted with low polar solvents. The thermal stability of antimicrobial substances decreased with heating time at $100^{\circ}C$. S. typhimurium was more sensitive to herbal extracts at $100\;and\;121^{\circ}C$ than B. subtilis.

• Journal of the Korean Chemical Society
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• v.28 no.3
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• pp.163-169
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• 1984

The transport rates of $K^+$ion through CHCl$_3$ liquid membrane containing dibenzo-18-crown-6(DBC) as a carrier molecule have been determined at $25^{\circ}C$. The transport rates depend highly on the ion concentration and on the nature of anion. It is concluded that $K^+$ions are transported in the form of ion-pair. In the case of potassium picrate, however, it is found that the transport proceeds with the formation of the incomplete ion-pair in the concentration less than 1.0 ${\times}10^{-3}$M of picrate, while with the complete formation of ion-pair in the concentration more than 1.0 ${\times}10^{-3}$M of picrate. Seven steps of the transport process are suggested and they can be illustrated in terms of energy barrier model as a function of the position of ionic species in the membrane.