• Journal of Ocean Engineering and Technology
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• v.26 no.4
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• pp.50-56
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• 2012

When a liquid cargo tank is partially filled with fluid, internal impact loads can be occurred from the vessel's motions. In this study, liquid sloshing problems with a thin top layer of particles with a lighter density than water and the coupling effects of the liquid-sloshing/vessel-motion were investigated in order to reduce the sloshing-induced impact loads. The PNU-MPS (Pusan-National-University-modified Moving Particle Simulation) method for solving the liquid motion inside a tank and the CHARM3D BEM (Boundary Element Method) based time-domain ship motion analysis program for vessel-motion simulation were coupled. From the simulation results, we could see that the floaters seemed to be quite effective at reducing the sloshing impact loads in the case of tank-only sloshing problems, but not as much for the coupling problem with vessel motion.

• Journal of Intelligence and Information Systems
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• v.7 no.1
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• pp.1-15
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• 2001

Recently, Internet based Electronic Commerce is recognized as one of the alternatives for strengthening sales power of small and medium companies. However, small and medium manufacturers can't adjust properly to the new environment because they are in short of money, personnel, and technology. To cope with this problem, this paper deals with the development of virtual manufacturing agent to support sales agent. The sales activity of most of parts manufacturing companies is based on orders of buyers. The process of promotion, receipt and selection of orders of the parts manufacturing is closely coupled with the load status of the production lines. On deciding whether to accept an order or not, as well as negotiating with buyers, sales person needs information such as load and schedule of production lines, manufacturability of the order. Therefore, the functions of virtual manufacturing agents manufacturability analysis, process planning, and scheduling are key features in developing an agent of sales activity for the parts manufacturing business. While most of research on virtual manufacturing system so far is focused on the simulation of each product, this paper deals with the development of agent assisting internet-based product sales by supporting production information promptly. The pilot system of virtual manufacturing agent is implemented using KQML-based agent template and Java-based expert system shell for a small molding company.

• Korean Journal of Remote Sensing
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• v.27 no.1
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• pp.9-15
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• 2011

Since PAN(panchromatic) and MS(multispectral) imagery of pushbroom scanner have the offset between PAN and MS CCD(charge coupled device) in the focal plane, PAN and MS images are acquired at different time and angle. Since clouds are fast moving objects, they should lead mis-registration problem with wrong matching points on clouds. The registration of cloudy imagery to recognize and remove the contamination of clouds can be categorized into three classes: (1) cloud is considered as nose and removed (2) employing multi-spectral imagery (3) using multi-temporal imagery. In this paper, method (1) and (3) are implemented and analysed with cloudy pushbroom scanner images.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.1
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• pp.72-78
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• 2008

In this study, advanced (fluid-structure interaction (FSI)) analysis system has been developed in order to predict turbine cascade performance with blade deformation effect due to aerodynamic loads. Intereference effects due to the relative movement of the rotor cascade with respect to the stator cascade are also considered. Reynolds-averaged Navier-Stokes equations with one equation Spalart-Allmaras and two-equation k-ω SST turbulence models are solved to accurately predict fluid dynamic loads considering flow separation effects. A fully implicit time marching scheme based on the (coupled Newmark time-integration method) with high artificial damping is efficiently used to compute the complex fluid-structure interaction problem. Predicted aerodynamic performance considering structural deformation effect of the blade shows somewhat different results compared to the case of rigid blade model. Cascade performance evaluations for different elastic axis positions are importantly presented and its aeroelastic effects are investigated.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.10
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• pp.859-867
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• 2007

The objective of this study is to develop and validate a numerical method which can handle the multi-rotor aerodynamic characteristics. For the purpose of power estimation, table look-up method is implemented to the existing unsteady panel code that is coupled with a time-marching free wake model. Also, the Reynolds number scaling is implemented for the application to various regions of Reynolds number. The computed results are validated against the available experimental data for coaxial and tandem rotors. In the validation case for the coaxial rotor, more accurate result is acquired when the thickness effect is considered. The wake instability problem occurs at a particular separation distance between the rotors for tandem rotors. The wake instability is avoided by setting the single-rotor wake geometry as the initial wake geometry for the multi-rotor analysis. The estimated result for rotor separation effect is compared with the result of the momentum theory.

• Textile Coloration and Finishing
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• v.21 no.5
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• pp.51-57
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• 2009

Since heavy metal pollution is a significant global environmental problem and very dangerous to human health, the improved methods for detecting heavy metals are required recently. Colorimetric chemosensors are now considered as one of the most effective analytical method used in the environment monitoring. New direct dyes having the function of colorimetric chemosensors were synthesized. When metal ions such as $Al^{3+}$, $Ca^{2+}$, $Cd^{2+}$, $Cr^{3+}$, $Cu^{2+}$, $Fe^{2+}$, $Fe^{3+}$, $Hg^{2+}$, $Li^+$, $Mg^{2+}$, $Na^+$, $Ni^{2+}$, $Pb^{2+}$ and $Zn^{2+}$ were added each solution of new direct dyes, the color of solution was changed and can be easily detected with naked eyes without expensive experimental equipment such as atomic absorption spectrometer (AAS) or inductively coupled plasma?mass spectrometer (ICP-MS). The new benzidine analogues were diazotized and reacted with couplers such as H-acid, J-acid, Chromotropic acid, Nevill-winther acid and gamma acid to synthesize new direct dyes. The structures of the new direct dyes were confirmed by high resolution mass spectrometer (FAB ionization) and evaluated with UV-Vis spectroscopy. The UV-VIS spectroscopy was measured for the dye solutions by adding various concentrations of metal ions. It was observed that the absorbance in UV-Vis spectra was changed as the heavy metal ions were added.

• Journal of Korean Society for Atmospheric Environment
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• v.18 no.E1
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• pp.1-12
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• 2002

One technique for determining dry acid deposition fluxes involves measurement of time - averaged ambient concentrations of dry acid deposition species using filter packs (FP) coupled with estimates of mean deposition velocities for the exposure period. A critical problem associated with filter pack data comparisons between various field sampling networks is the use of diverse sampling flow rates and duration protocols. Field experiments were conducted to evaluate the effects of varying sampling flow rates, from 1.5 to 10 standard liters per minute, on total nitrate and sulfate measurements of specific dry acid deposition species . Collocated FP samplers were used to determine sampling and analysis data reproducibility and representativeness . Ambient air samples were simultaneously collected using groups of filter packs operated at various flow rates over identical 7 day periods. The species measured were sulfur dioxide, particulate sulfate , nitric acid and particulate nitrate. Statistical results (ANOVA; alpha level 5%) showed that neither the low nor high sampling flow rates caused a significant difference in the measurements of total sulfate and adjusted total nitrate (ATN) . However, it was concluded that for high flow rate sampling measurements, total nitrate (TN) could be affected during extended sampling durations because of potential nitric acid overloading and breakthrough. Although the previous workers (Costello, 1990; Quillian, 1990) used much higher sampling flow rates (~ 17 sLpm) than employed here, it was assumed that for a high loading (> 50$\mu\textrm{g}$ HNO$_3$) of nitric acid on the Nylon filters, a significant fraction (~10%) of nitric acid could pass through the Nylon filters and be collected on the carbonate impregnated filters. It was concluded that even at the highest sampling flow rate employed (10 sLpm) at the Cary Forest site, nitric acid breakthrough was less than 10% of the total HNO$_3$ collected. However, for a heavily polluted urban airshed or with longer sampling times , higher filter loadings could result in substantial nitric acid breakthrough and HNO$_3$concentrations would be underestimated.

• Journal of Microbiology and Biotechnology
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• v.25 no.3
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• pp.358-365
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• 2015

ε-Poly-L-lysine (ε-PL) is a homopolymer of L-lysine molecules connected between the epsilon amino and alpha carboxyl groups. This polymer is currently used as a natural preservative in food. Insufficient biomass is a major problem in ε-PL fermentation. Here, to improve cell growth and ε-PL productivity, various nitrogen-rich nutrients were supplemented into flask cultures after 16 h cultivation, marking the onset of ε-PL biosynthesis. Yeast extract, soybean powder, corn powder, and beef extract significantly improved cell growth. In terms of ε-PL productivity, yeast extract at 0.5% (w/v) gave the maximum yield (2.24 g/l), 115.4% higher than the control (1.04 g/l), followed by soybean powder (1.86 g/l) at 1% (w/v) and corn powder (1.72 g/l) at 1% (w/v). However, supplementation with beef extract inhibited ε-PL production. The optimal time for supplementation for all nutrients examined was at 16 h cultivation. The kinetics of yeast-extract-supplemented cultures showed enhanced cell growth and production duration. Thus, the most commonly used two-stage pH control fed-batch fermentation method was modified by omitting the pH 5.0-controlled period, and coupling the procedure with nutrient feeding in the pH 3.9-controlled phase. Using this process, by continuously feeding 0.5 g/h of yeast extract, soybean powder, or corn powder into cultures in a 30 L fermenter, the final ε-PL titer reached 28.2 g/l, 23.7 g/l, and 21.4 g/l, respectively, 91.8%, 61.2%, and 45.6% higher than that of the control (14.7 g/l). This describes a promising option for the mass production of ε-PL.

• Clinical and Experimental Pediatrics
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• v.49 no.11
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• pp.1125-1139
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• 2006

In 1991, the Ministry of Health & Social affairs adopted a nationwide service program for neonatal screening of phenylketonuria, galactosemia, maple syrup urine disease, homocystinuria, histidinemia & congenital hypothyroidism for newborns delivered from low class pregnant women registered in health centers. Government decreased the test items from six to two, PKU & congenital hypothyroidism to increase test numbers with same budget from 1995. Government decided to test PKU & hypothyroidism for all newborns from 1997. 78 laboratories wanted to participate for neonatal screening test in 1999. Government didn't decide laboratory center for a certain district and placed responsibility on free competition. Government are planning to test 573,000 newborns from 1998, Government decided to screen 6 items PKU, congenital hypothyroidism, maple syrup urine disese, homocystinuria, galactosemia and congenital adrenal hyperplasia from 2006. 17 laboratores are participating now. The cost of screening test is supported by both the federal government and local government on a 40-60 basis. In case a patient with an inherited metabolic disease is diagnosed by screening of government program, special milk is provided at government's expense. Interlaboratory quality control was started 6 times a year from 1994. According to the government project, 3,707,773 newborns were screened. 86 PKU, 718 congenital hypothyroidism were detected. So incidence of PKU is 1/43,114 and congenital hypothyroidism is 1/4,612. Maeil dairy company produced new special formula for PKU, MMA and PA, MSUD, urea cycle disorder, homocystinuria, isovaleric acidemia from Oct. 1999. The cost benefit of performing screening procedures coupled with treatment has been estimated to be as high as 1.77 times in PKU, 11.11 times in congenital hypothyroidism than cost without screening. We are trying to increase the budget to test all newborns for Tandem mass sereening & Wilson disease from 2008. Now it is a very important problem to decrease laboratory numbers of neonatal screening in Korea. So we are considering 4-5 central laboratories which cover all newborns and are equipped with tandem mass spectrometer & enzyme immunoassay for TSH, 17OHP & enzyme colorimetric assay for galactose.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1995.04a
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• pp.869-879
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• 1995

The new field of learning control develops controllers that learn to improve their performance at executing a given task, based on experience performing this task. The simplest forms of learning control are based on the same concept as integral control, but operating in the domain of the repetitions of the task. In the previous paper, I had studied the use of such controllers in a decentralized system, such as a robot with the controller for each link acting independently. The basic result of the paper is to show that stability of the learning controllers for all subsystems when the coupling between subsystems is turned off, assures stability of the decentralized learning in the coupled system, provided that the sample time in the digital learning controller is sufficiently short. In this paper, we present two examples. The first illustrates the effect of coupling between subsystems in the system dynamics, and the second studies the application of decentralized learning control to robot problems. The latter example illustrates the application of decentralized learning control to nonlinear systems, and also studies the effect of the coupling between subsystems introduced in the input matrix by the discretization of the system equations. The conclusion is that for sufficiently small learning gain, and sufficiently small sample time, the simple learning control law based on integral control applied to each robot axis will produce zero tracking error in spite o the dynamic coupling in the robot equations. Of course, the results of this paper have much more general application than just to the robotics tracking problem. Convergence in decentralized systems is seen to depend only on the input and output matrices, provided the sample time is suffiently small.