• Journal of the Earthquake Engineering Society of Korea
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• v.13 no.4
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• pp.67-76
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• 2009

Recently, the active interaction control (AIC) system was proposed as a semi-active control system. The AIC system consists of a primary structure and an auxiliary structure. The objective of the AIC system is to control the response of the primary structure through engagement and disengagement between the primary and auxiliary structures. Previous switching control algorithms have been shown to be effective in reducing the response of the primary structure. However, they have the main drawback of requiring an excessive engagement-disengagement frequency and high interaction force. In this paper, the regions in which the switching is activated and the regions in which the switching is deactivated are described separately, to effectively determine the engagement or the disengagement. The general relationship between the switching regions and the deactivated switching regions selected according to the engagement-disengagement conditions is described within the newly-developed comprehensive switching framework. The proposed engagement-disengagement conditions are designed within a comprehensive switching framework, to reduce engagement-disengagement frequency and interaction force. Furthermore, the effect of a control sampling period on the AIC system is explained in terms of the engagement-disengagement frequency. The effectiveness of the proposed algorithms and the effect of the control sampling period are considered for a single degree of freedom model under free vibration. It is observed that increasing the duration of stay by using a large control sampling period prevents the AIC system from activating the possible chance of switching. The proposed algorithms are shown to be effective, both in restricting ineffective switching and in reducing interaction force.

• Journal of the Korean Chemical Society
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• v.48 no.6
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• pp.583-589
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• 2004

In a stream of aqueous sample, trace arsenic ions were quantitatively coprecipitated and detected in ICP-AES through hydride generation. In was used as a coprecipitating reagent. The precipitate was collected on a filter and dissolved by HCl. The eluted As was sent into the reaction coil to generate hydrides and analyzed by ICP. With optimal conditions, and with a sample of 0.3 mL, an enrichment of 70 was obtained with the sampling speed of 10/hr. When compared with coprecipitation and hydride generation technique, the sensitivity was increased by 7 and 10 times, respectively. The limit of detection limit$(3{\sigma})$ was 0.020 ${\mu}g\;L^{-1}$ and the precision was 7-10%. Separation of $As^{3+}\;and\;As^{5+}$ were possible using citric acid in hydride generation.

• Korean Journal of Microbiology
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• v.49 no.3
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• pp.253-261
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• 2013

The purpose of this study was to investigate the aflatoxin $B_1$ binding of lactic acid bacteria (LAB) isolated from Korean traditional soybean paste and to evaluate the effect of incubation conditions and physico-chemical factors on the binding ability of LAB to this mutagen. The amount of aflatoxin $B_1$ bound by Enterococcus faecium DJ22, Lactobacillus fermentum DJ35, Lactobacillus rhamnosus DJ42, and Lactobacillus pentosus DJ47 was strain specific with the percent bound ranging from 19.3% to 52.1%. However, Enterococcus faecalis DJ14, Lactobacillus panis DJ29, and Pediococcus halophilus DJ50 strains did not exhibit any of the binding ability to aflatoxin $B_1$. For most strains, the binding ability was significantly affected by the environmental conditions such as the aflatoxin $B_1$ level, incubation time and temperature, and the initial cell count of LAB. The stability of the aflatoxin $B_1$-bacteria complexes was significantly more unstable after washing. In addition, the binding stability between viable and nonviable cells was not statistically significant. Treatment with heating, acidic pH, ${\alpha}$-amylase, protease, lysozyme, or sodium metaperiodate caused a significant (P<0.05) decrease in aflatoxin $B_1$ binding for the tested strains, suggesting that carbohydrates or proteins in the cell walls may be involved in aflatoxin $B_1$ binding ability. Since the aflatoxin $B_1$ binding of LAB was significantly reduced (P<0.05) by the pretreatment of the urea, the binding force observed in this study may have resulted from hydrophobic interaction.

• Journal of KIISE:Software and Applications
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• v.27 no.3
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• pp.290-301
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• 2000

Most morphological analysis methods require repetitive procedures of input character code conversion, segmentation and lemmatization of constituent morphemes, filtering of candidate results through looking up lexicons, which causes run-time inefficiency. To alleviate such problem of run-time inefficiency, many systems have introduced the notion of 'pre-analysis' of words. However, this method based on pre-analysis dictionary of surface also has a critical drawback in its practical application because the size of the dictionaries increases indefinite to cover all words. This paper hybridizes both extreme approaches methodologically to overcome the problems of the two, and presents a method of morphological analysis based on pre-analysis of partial words. Under such hybridized scheme, most computational overheads, such as segmentation and lemmatization of morphemes, are shifted to building-up processes of the pre-analysis dictionaries and the run-time dictionary look-ups are greatly reduced, so as to enhance the run-time performance of the system. Moreover, additional computing overheads such as input character code conversion can also be avoided because this method relies upon no graphemic processing.

• KSBB Journal
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• v.16 no.1
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• pp.41-47
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• 2001

H. pylori is known to be a key pathogen of chronic gastric and duodenal ulcers. Bacterial adhesion to hosts is an essential step for bacterial infection and the inhibition of this adhesion provides a possible method for the treatment of the infection. The inhibitory effect of antibody lgY, produced from immunized hens with H. pylori antigen, was studied in vitro. The inhibition of H. pylori adhesion to AGS was as high as 90% using 0.5mg/ml of lgY, and almost 80% of the detachmentwas also achieved. The inhibitory effect of adhesion-inhibition candidates was investigated. Additives in combination with lgY increased the adhesion-inhibiting effect by about 30-50%. However, the adhesion molecules of H. pylori were varied and complex, therefore the further studies are necessary to develop an adhesion inhibitor and effective enough to be employed for the treatment of H.pylori, in vivo.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.5
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• pp.787-791
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• 2012

Bloods from slaughtered Korean native cattle (Hanwoo : Bos taurus coreanae) can be used in agriculture with various beneficial effects on the environment. This study was performed to find out the effect of the application of calcium and germanium, which are chelated with peptides made of cattle bloods on the absorption of them by cherry tomato (Lycopersicon esculentum Mill.). Peptide was purified by enzymatic hydrolysis and ultrafiltration from serum protein, which is composed of Asp, Glu, Lue etc. Chelated Ca and Ge were produced by reacting the peptide with $CaCl_2$ and Ge-$132^{(R)}$. Then, they were applied to cherry tomato during cultivation period at the rate of $300mL{\times}3times$ (10 days interval) for each tomato tree. Application of chelated-Ca increased the Ca contents in leaves and fruits of cherry tomato showing as 19.9% and 23.4% in newerly prepared chelated-Ca-200 ($200mg\;L^{-1}$), 8.1% and 6.8% in commecrial Calciolid Ca-300 ($300mg\;L^{-1}$) compared to 3152.6 and $63.2mg\;kg^{-1}$ in control, respectively. Application of chelated-Ge showed the increase in the germanium contents in both leaves and fruits of cherry tomato by over 6 times than those of control and over 4 times than Ge $132^{(R)}$-20 application. As a result of this study, it seemed that the application of chelated-Ca and chelated-Ge would be more effective than the existing commertial one in the absorption of calcium and germanium by cherry tomato.

• Journal of Biomedical Engineering Research
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• v.24 no.3
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• pp.217-231
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• 2003

Coded excitation with complementary Golay sequences is an effective means to increase the SNR and penetration of ultrasound imaging. in which the two complementary binary codes are transmitted successively along each scan-line, reducing the imaging frame rate by half. This method suffers from low frame rate particularly when multiple transmit focusing is employed, since the frame rate will be further reduced in proportion to the number of focal zones. In this paper. a new ultrasound imaging technique based on simultaneous multiple transmit focusing using modified orthogonal Golay codes is proposed to improve lateral resolution with no accompanying decrease in the imaging frame rate, in which a pair of orthogonal Golay codes focused at two different focal depths are transmitted simultaneously. On receive, these modified orthogonal Golay codes are separately compressed into two short pulses and individually focused. These two focused beams are combined to form a frame of image with improved lateral resolution. The Golay codes were modified to improve the transmit power efficiency (TPE) for practical imaging. Computer simulations and experimental results show that the proposed method improves significantly the lateral resolution and penetration of ultrasound imaging compared with the conventional method.

• Journal of the Korea Computer Graphics Society
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• v.20 no.4
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• pp.9-16
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• 2014

This paper proposes a novel method that couples fluid and deformation/fracture. Our method considers two interaction types: fluid-object interaction and fluid-fluid interaction. In fluid-fluid interaction, we simulate water and smoke separately and blend their velocities in the intersecting region depend on their densities. Our method separates projection process into two steps for each of water and smoke. This reduces the number of grid cells required for projection in order to optimize the number of iterations for convergence and improve stability of the simulation. In water projection step, smoke region regarded as the cells with Dirichlet boundary condition. The smoke projection step solves water region with Neumann boundary condition. To take care of fluid-object interaction, we make use of the fluid pressure to update velocities of the each of the mass points so that the object can deform or fracture. Although our method doesn't provide physically accurate results, the various examples show that our method generate appealing visuals with good performance.

• Korean Journal of Microbiology
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• v.30 no.4
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• pp.310-315
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• 1992

Absorption of $\textrm{Pb}^{2-}$ from aqueous solution was studied using Staphylococcus epidermidis. Cells of exponential phase were employed as absorbents. Uptake ratio defined as the ratio of amount of $\textrm{Pb}^{2+}$ absorbed to that of initial $\textrm{Pb}^{2+}$. Absorption of $\textrm{Pb}^{2+}$ increased with increase in cell concentration. while amount of $\textrm{Pb}^{2+}$ per unit cell mass decreased. Uptake ratio of $\textrm{Pb}^{2+}$ augmented and then diminished after exhibiting a maximum as the pH of the solution increased. Equilibrium absorption of $\textrm{Pb}^{2+}$ deviated from Freundlich isotherm especially at higher concentration of $\textrm{Pb}^{2+}$ due to the precipitation phenomena. HCI and EDTA were founded to desorb $\textrm{Pb}^{2+}$ more effectively than $\textrm{Na}_{2}\textrm{CO}_{3}$ or $\textrm{NaHCO}_{3}$. After 10 cycles of absorption and desorption. $\textrm{Pb}^{2+}$ absorption capability remained almost unchanged and the biomass had leaked out 30-40 wt/%. Uptake ratio of Pb2+ decreased in the presence of other heavy metal ions due to the competitive absorption The inhibition of $\textrm{Pb}^{2+}$ absorption appeared to have a strong correlation with ionic radius of the competing ions. Especially $\textrm{Cr}^{3-}$, $\textrm{Co}^{2+}$ or $\textrm{Fe}^{2+}$ having smaller ionic radius depressed more significantly the uptake of $\textrm{Pb}^{2+}$ than any other metal ions tested.