• International Journal of Naval Architecture and Ocean Engineering
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• v.10 no.6
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• pp.683-691
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• 2018

Numerical simulations of turbulent flows around KCS have been performed to study the sensitivity of ship resistance to wall-adjacent grids and disclose the influence of near-wall treatment on the sensitivity of ship resistance. The resistance coefficients of viscous and pressure forces were compared when using realizable $k-{\varepsilon}$ and SST $k-{\omega}$ turbulence models in structured and unstructured grids, respectively. The calculation of friction velocity was found to be mainly responsible for the reduction of viscous and total resistances when the height of wall-adjacent cells increased. Since the assumption of equilibrium state between turbulent production and dissipation was not met in a bulbous bow, it was more reasonable to iteratively calculate the friction velocity from empirical laws of the wall for near-wall treatment rather than explicitly estimate it from the turbulent kinetic energy.

• Bulletin of the Korean Chemical Society
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• v.28 no.7
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• pp.1109-1113
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• 2007

Acetohydroxyacid synthase (AHAS, EC 2. 2. 1. 6) is the enzyme that catalyses the first step in the common pathway of the biosynthesis of the branched chain amino acids, valine, leucine and isoleucine. For the first time, the AHAS gene from Bacillus anthracis was cloned into the expression vector pET28a(+), and was expressed in the E. coli strain BL21(DE3). The purified enzyme was checked on 12% SDS-PAGE to be a single band with molecular weight of 65 kDa. The optimum pH and temperature for B. anthracis AHAS was at pH 7.5 and 37 oC, respectively. Kinetic parameters of B. anthracis were as follows: Km for pyruvate, K0.5 for ThDP and Mg2+ was 4.8, 0.28 and 1.16 mM respectively. AHAS from B. anthracis showed strong resistance to three classes of herbicides, Londax (a sulfonylurea), Cadre (an imidazolinone), and TP (a triazolopyrimidine). These results indicated that these herbicides could be used in the search for new anti-bacterial drugs.

• Journal of Environmental Science International
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• v.30 no.6
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• pp.429-439
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• 2021

Food waste is both an industrial and residential source of pollution, and there has been a great need for food waste reduction. As a preliminary step in this study, waste reduction is quantitatively modeled. This study presents two models based on kinetics: a simple kinetic model and a mass transport-shrinking model. In the simple kinetic model, the smaller is the reaction rate constant ratio k₁, the lower the rate of conversion from the raw material to intermediate products. Accordingly, the total elapsed reaction time becomes shorter. In the mass transport-shrinking model, the smaller is the microbial decomposition resistance versus the liquid mass transfer resistance, the greater is the reduction rate of the radius of spherical waste particles. Results showed that the computed reduction of waste mass in the second model agreed reasonably with that obtained from a few experimantal trials of biodegradation, in which the microbial effect appeared to dominate. All calculations were performed using MATLAB 2020 on PC.

• Structural Engineering and Mechanics
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• v.39 no.3
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• pp.427-447
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• 2011

The progressive collapse phenomenon is generally regarded as dynamic. Due to the impracticality of nonlinear dynamic computations for practitioners, an interest arises for the development of equivalent static pushover procedures. The present paper proposes a methodology to identify such a procedure for sudden column removals, using energetic evaluations to determine the pushover loads to apply. In a dynamic context, equality between the cumulated external and internal works indicates a vanishing kinetic energy. If such a state is reached, the structure is sometimes assumed able to withstand the column removal. Approximations of these works can be estimated using a static computation, leading to an estimate of the displacements at the zero kinetic energy configuration. In comparison with other available procedures based on such criteria, the present contribution identifies loading patterns to associate with the zero-kinetic energy criterion to avoid a single-degree-of-freedom idealisation. A parametric study over a family of regular steel structures of varying sizes uses non-linear dynamic computations to assess the proposed pushover loading pattern for the cases of central and lateral ground floor column failure. The identified quasi-static loading schemes are shown to allow detecting nearly all dynamically detected plastic hinges, so that the various beams are provided with sufficient resistance during the design process. A proper accuracy is obtained for the plastic rotations of the most plastified hinges almost independently of the design parameters (loads, geometry, robustness), indicating that the methodology could be extended to provide estimates of the required ductility for the beams, columns, and beam-column connections.

• Proceedings of the Korean Society for Bioinformatics Conference
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• 2005.09a
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• pp.191-196
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• 2005

Genetic networks are a key to unraveling dynamic properties of biological processes and regulation of genes plays an essential role in dynamic behavior of the genetic networks. A popular characterization of regulation of the gene is a kinetic model. However, many kinetic parameters in the genetic regulation have not been available. To overcome this difficulty, in this report, state-space approach to modeling gene regulation is presented. Second-order systems are used to characterize gene regulation. Interpretation of coefficients in the second order systems as resistance, capacitance and inductance is studied. The mathematical methods for transient response analysis of gene regulation to external perturbation are investigated. Criterion for classifying gene into three categories: underdamped, overdamped and critical damped is discussed. The proposed models are applied to yeast cell cycle gene expression data.

• The Korean Journal of Zoology
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• v.30 no.3
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• pp.301-310
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• 1987

본 실험에서는 반SP와 thermotolerance 사이에 어떠한 상관관계가 있는지를 알아보기 위하여, 생쥐 SCK 종양세포에서 heat(45$^{\circ}$, 46$^{\circ}C$)처리가 단백질 합성과 세포의 생존에 미치는 영향을 비교하여 보았다. 그 결과 heat 처리를 받은 세포는 HS$\ulcorner$(70K, 87K)를 측이하게 많이 합성했으며, 다음 heat를 받았을 때는 높은 생존율을 꼬였다. 그리고 이러한 thermotolerance가 생성되고 감퇴되는 kinetics는 HSP가 합성되고 감퇴되는 kinetics와 연관성을 보여 주었다. 이러한 결과로 HSP는 heat shock로부터 세포를 보호하는 데 중요한 역할을 할 수 있다고 생 각된다. 아울러, glycerol을 처리하여 HSP의 합성을 봉쇄시켰을 경우에도 열에 대해 저항성을 갖게 되는 실험결과로 미루어, 세포가 갖게 되는 heat resistance에는 (1) HSP의 합성을 초래하지 않는 요인에 의해 유도되는 heatprotection과 (2) 열처리 등의 결과 합성되는 반SP에 의해 유도되는 thermotolerance의 두가지 경우가 있을 것으로 추론할 수 있었다.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.3
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• pp.299-305
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• 2019

This study was initiated to solve the difficulties of aged and female workers in agriculture society due to aging and demise of young people. In the case of the conventional elevated lift, the risk of exposure to uneven road or work environment, not the difficulty of professional qualification and operation, and the risk of exposure to the uneven road or working environment, were also studied based on previous researches so that women could easily and efficiently perform productive agriculture. First, the simulation was carried out through the prediction model of traction performance using the object of agricultural forklift, and the soil of the Kimhae city in Gyeongnam (34.125kPa, internal friction angle 35.294deg, external friction angle 13.620deg, Adhesion force 5.750 kPa, average cone index 0-15 cm cl, 1001.8 kPa). In the case of the forklift for simulation, the driving force and the kinetic resistance prediction modeling of the agricultural electric forklift are modeled. Based on this model, the motor control drive adopts the 1232E model, which is a drive dedicated to AC motor, and divides the two drivers into master and slave And the model for the simulation was designed to control motor drive, hydraulic drive, and various outputs on the main PCB. The simulation model is undergoing continuous simulation, modification and supplementation. Based on this research, we will continue research for development of safer and more efficient agricultural electric forklift.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.747-750
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• 1995

As railway trains run faster high performance braking system are necessary because more energy needs to be dissipated due to increased kinetic energy. In this work a portable computer based prediction system for emergency braking distance has been developed. The algorithm for the system is based on braking theory and empirical results of actual braking test. The computer is connected to the sensors to measure the velocity and the braking pressure in real train. It is expected that this system will be utilized to predict emergency braking distance during actual operation of the train

• Proceedings of the Korea Air Pollution Research Association Conference
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• 1999.10a
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• pp.225-228
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• 1999

The formation of dioxin (term used here to refer to both polychlorinated dibenzo-p-dioxins, PCDDS, and dibenzofurans, PCBFs) in combustion processes is of concern because of the extreme toxicities of some of these compounds and because of their resistance to degradation in the environment. The number and location of chlorine substituents differentiate dioxin homologues and isomers, respectively. There are a total of 75 PCDD congeners and 135 PCDF congeners.(omitted)

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2000.11a
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• pp.302-306
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• 2000

In case of applying electrokinetic remediation, magnitude of electric current is one of major factors for estimation of contaminant transport. In practice, electric current provide determination of electric conductivity based on specimen resistance. Electric current variation is produced during Electrokinetic remediation test. Electric current is decreased by expotential function according to time in condition of constant voltage. This can be interpreted as precipitation effect by OH$^{-10}$ generation in a cathode.