• Proceedings of the Korea Concrete Institute Conference
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• 1992.04a
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• pp.47-52
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• 1992

The entire nonlinear behavior of reinforced concrete frames up to collapse, is analyzed by the displacement control method and the combined layered and nonlayered method. All of the rigidities of section are calculated approximately by a sum over all the layers for the layered method, are used the integral values over the cross section area for the nonlayered method. The spurious sensitivity to the chosen element size in the result of analysis by finite element method for the materials with strain-softening can be overcome by modifying the strain distribution based on the concept of fracture energy at plastic hinge considering the applied axial load.

• Proceedings of the Korean Biophysical Society Conference
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• 2001.06a
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• pp.62-62
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• 2001

Serpins inhibit target proteases by forming tight acyl complex Via incorporation of the reactive center loop into ${\beta}$-sheet A. Metastability of the serpins control the translocation of the protease from the initial binding site to the opposite pole of the serpin. Recently the crystal structure of a serpin-protease complex revealed that the active site of the protease is distorted.(omitted)

• Journal of The Korean Society of Agricultural Engineers
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• v.47 no.5
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• pp.27-39
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• 2005

In the recent design of high ductile fiber-reinforced ECC (engineered cementitious composite), optimizing both processing and mechanical properties for specific applications is critical. This study presents an innovative method to develop new class ECCs, which possess the different fluid properties to facilitate diverse types of processing (i.e., self-consolidating or shotcrete processing) while maintaining ductile hardened properties. In the material design concept, we employ a parallel control of fresh and hardened properties by using micromechanics and cement rheology. Control of colloidal interaction between the particles is regarded as a key factor to allow the performance of the specific processing. To determine how to control the particle interactions and the viscosity of cement suspension, we first introduce two chemical admixtures including a highly charged polyelectrolyte and a non-ionic polymer. Optimized mixing steps and dosages we, then, obtained within the solid concentration predetermined based on micromechanical principle. Test results indicate that the rheological properties altered by this approach were revealed to be highly effective in obtaining the desired function of the fresh ECC, allowing us to readily achieve hardened properties, represented by pseudo strain-hardening behavior in uniaxial tension.

• Journal of Microbiology and Biotechnology
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• v.23 no.9
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• pp.1304-1307
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• 2013

Growth of Microcystis aeruginosa could be inhibited significantly within 24 h by the extracellular substances prepared from Aeromonas sp. strain FM. During the treatment, the concentration of extracellular soluble carbohydrates increased significantly in algal culture. Morphological and ultrastructural changes in M. aeruginosa cells, including breakage of the cell surface, secretion of mucilage, and intracellular disorganization of thylakoids, were observed. HPLC-MS analysis showed that the extracellular substances of Aeromonas sp. strain FM were a mixture of free amino acids, tripeptides, and clavulanate. Among these, the algaelysis effects of lysine and clavulanate were confirmed.

• Journal of Microbiology and Biotechnology
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• v.19 no.7
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• pp.734-741
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• 2009

Recently, strains of methicillin-resistant Staphylococcus aureus (MRSA) with reduced susceptibility to vancomycin (VCM) have been clinically isolated. The antibacterial activity of a new drug, linezolid (LZD), in such a strain was evaluated by measuring bacterial metabolic activity. A total of 73 MRSA strains having various susceptibilities to VCM were subjected to a novel and highly sensitive chemiluminescence-based assay. LZD MIC in the tested strains, measured by the microbroth dilution method, was within the range 1-4 mg/l (mostly ${\leq}2$mg/l), except for one LZD-resistant strain (NRS127; MIC=7 mg/l), and showed no correlation with VCM resistance. The chemiluminescence assay demonstrated that bacterial metabolic activity was strongly suppressed with increasing LZD concentration. The chemiluminescence intensity curve had a low baseline activity without tailing in most strains. The present results suggest that LZD has strong antibacterial activity against MRSA strains, and would be effective for treatment of infections that are poorly responsive to VCM. The chemiluminescence assay facilitated sensitive and discriminative susceptibility testing within a relatively short time.

• The Plant Pathology Journal
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• v.32 no.3
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• pp.273-280
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• 2016

Most biocontrol agents for plant diseases have been isolated from sources such as soils and plants. As an alternative source, we examined the feces of tertiary larvae of the herbivorous rhino beetle, Allomyrina dichotoma for presence of biocontrol-active microbes. The initial screen was performed to detect antifungal activity against two common fungal plant pathogens. The strain with strongest antifungal activity was identified as Bacillus amyloliquefaciens KB3. The inhibitory activity of this strain correlated with lipopeptide productions, including iturin A and surfactin. Production of these surfactants in the KB3 isolate varied with the culture phase and growth medium used. In planta biocontrol activities of cell-free culture filtrates of KB3 were similar to those of the commercial biocontrol agent, B. subtilis QST-713. These results support the presence of microbes with the potential to inhibit fungal growth, such as plant pathogens, in diverse ecological niches.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.7
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• pp.524-529
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• 2016

We describe the design and fabrication of a two-axis force/torque sensor with parallel-plate beams (PPBs) and single beams for measuring force and torque in hip-joint rehabilitation exercise using a lower rehabilitation robot. The two-axis force/torque sensor is composed of an Fz force sensor and a Tz torque sensor, which detect z direction force and z direction torque, respectively. The two-axis force/torque sensor was designed using the FEM (Finite Element Method) and manufactured using strain gages. The characteristics experiment of the two-axis force/torque sensor was carried out. The test results show that the interference error of the two-axis force/torque sensor was less than 0.64% and the repeatability error and the non-linearity of the two-axis force/torque sensor were less than 0.03%. It is thought that the developed two-axis force/torque sensor could be used for a lower rehabilitation robot.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.90.6-90
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• 2002

An active stick which has the variable force-feel characteristics is developed. A combined position and force control strategy is mechanized using a 2-axis built-in force sensor and LVDT. The 2-axis force sensor which measures the stick force felt by the operator is developed by using strain gages and appropriate instrumental amplifiers. A mathematical model of the active stick dynamics is derived, and compared with the experimental results. The frictional torque of the stick due to the mechanical contacts of several parts makes the experimental frequency responses to be dependent on the magnitude of excitation signal, and the precision closed loop control to be difficult. A friction observe...

• Journal of Bio-Environment Control
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• v.16 no.4
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• pp.388-394
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• 2007

To product the edible fresh shoots of Sedum sarmentosum in summer season, 4 local strains were cultivated with cutting propagation under 0, 30, 50, 70, 90% shading. Effect of shading on shoot growth, leaf chroma value, SPAD value, and bitterness were investigated at 35 days after cutting. Plant height, the number of node and leaf stem diameter in $30{\sim}90%$ shading were increased than in the control, and Pohang local strain had little-overgrowth shoot, thicker stem, a few brenches per shoot, and larger leaf compared to the other local strains. Fresh and dry weight under shading were increased than in the control, dry weight of pohang local strain was highest in 50% shading. Hunter L and b values were decreased out of proportion to higher shading rate. SPAD value in $50{\sim}90%$ shading was significantly lower than in the control. The bitterness of fresh shoot was decreased out of proportion to higher shading rate. In Summer season, producing the fresh shoot of S. sarmentosum was excellent in 50% shading, and Pohang local strain among 4 local strains was more stable and good in yield and quality under shading.

• Research in Plant Disease
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• v.26 no.1
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• pp.8-18
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• 2020

Red pepper, one of the major economic crops in Korea, is being affected by anthracnose disease caused by Colletotrichum acutatum. To control this disease, an antagonistic bacterial strain, Bacillus subtilis YGB36 identified by 16S rDNA sequencing, physiological and biochemical analyses is used as a biological control agent. In vitro screening revealed that the strain YGB36 possess strong antifungal activity against the pathogen Cylindrocarpon destructans. The strain exhibited cellulase, protease, amylase, siderophore production and phosphate solubility. In vitro conidial germination of C. acutatum was most drastically inhibited by YGB36 cell suspensions (10⁶ cfu/ml) or culture filtrate. Development of anthracnose symptoms was reduced on detached immature green pepper fruits by treatment with cell suspensions, and its control value was recorded as 65.7%. The YGB36 bacterial suspension treatment enhanced the germination rate of red pepper seeds and promoted root development and growth under greenhouse conditions. The in vitro screening of fungicide and insecticide sensitivity test against YGB36 revealed that the bacterial growth was not affected by any of the insecticides, and 11 fungicides out of 21 used. Collectively, our results clearly suggest that the strain YGB36 is considered as one of the potential biocontrol agents against anthracnose disease in red pepper.