• KSBB Journal
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• v.30 no.6
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• pp.319-325
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• 2015

Arthrospira platensis (A. platensis) is one of the most explored cyanobacteria and has been studied for proteins, vitamins, pigment (chlorophyll and carotenoids) and fatty acid. In this study, we tested the effect of $NaHCO_3$ and $NaNO_3$ on the microalgae growth under photoautothrophic culture in A. platensis. As a result, cell growth and dry cell weight were increased in proportion to the $NaHCO_3$ and $NaNO_3$ concentration. Pigment (chlorophyll and carotenoids) contents of A. platensis were increased with proportion to $NaHCO_3$ concentration. But, the content of pigment (chlorophyll and carotenoids) in 100% $NaNO_3$ medium of A. platensis was the highest, 40%, 140% and 200% $NaNO_3$ medium with pigment content of A. platensis was reduced. In conditions of $NaHCO_3$ (50%) or $NaNO_3$ (40%) limitation, A. platensis could accumulate lipids to high as 1.7-fold and 1.3-fold.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.7 no.1
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• pp.65-73
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• 1987

An efficient plate bending finite element has been developed using higher-order inplane displacement profiles of the plate. The 6-noded, 21-d.o.f. triangular element including shear deformation effect has been derived from the plate-like continuum by the Galerkin's weighted residual method. Square plate examples were tested with selected element meshes and several aspect ratios for their static behavior under uniformly distributed load. The result of the example tests indicated consistently good performance of the present higher-order plate bending element in comparison with the thin and thick plate solution and other existing finite element solutions.

• Korean Journal of Community Nutrition
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• v.11 no.1
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• pp.98-107
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• 2006

This study was performed to test food preferences of the Korean elderly for Korean elderly menu development. The elderly subjects preferred steamed rice cooked with 1.2 times water than that with 1.5 times water (p < 0.001) , whole rice grain gruel than the gruel with ground grain (p < 0.05) . Green tea powder gruels developed as a snack, there were no significant differences in the preference of the elderly between gruel with different contents of green tea powder (2, 3, $4\%$). The preferences of the salt concentration of the soup were tested by using soybean sprout soup and soybean paste soup. The elderly preferred 0.7 - $0.8\%$ salted bean sprout soup and $7\%$ soybean paste soup. The elderly preferred Kimchi cut in widths of 1 - 2 cm than that in 0.5 cm. The elderly preferred sweeter grape jam ($67\%$ vs. $50\%$ or $37\%$ sugar content) and were not concerned about chewing seeds. This result could be useful to develop menus for the elderly. (Korean J Community Nutrition 11 (1): 98$\sim$107, 2006)

• Korean Journal of Community Nutrition
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• v.1 no.2
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• pp.260-268
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• 1996

This study aimed to develop an experimental animal model of duodenal ulcer for application to nutrition, and to verify the nutritional characteristics. The 7 different doses and 8 different injections of cysteamine and 2 kinds of diets with different casein levels(10%, 20%) were tested to examine the incidence and the process of duodenal ulcer in female Sprague-Dawley rats. The result showed that the duodenal ulcer was induced when rats fed 10% casein diet(for 9 days) were injected 6 times with 13mg/100g BW cysteamine. The first injection was conducted after 24 hours of fasting, followed by the 2nd shot after 3 hours. The following shots were repeated every 3 day(4th and 7th days). Duodenal ulcer was observed 3 days after the last injection by optical microscope and the naked eye. The characteristics of nitrogen bioavailability of duodenal ulcer model were as followings : 1) gastric emptying rate was faster, 2) trypsin activity at duodenum was higher, 3) total protein concentration at serum and nitrogen retention rate were lower than the control. (Korean J Community Nutrition 1(2) : 260-268, 1996)

• Transactions of the Korean Society of Mechanical Engineers A
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• v.22 no.2
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• pp.278-288
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• 1998

An efficient and useful method to improve the local stress field in a displacement-formulated finite element solution has been proposed using the theory of conjugate approximations for a stress field and the Loubignac's iterative method for a displacement field. Validity of the proposed method has been tested through three test examples, to improve the stress field and displacement field in the whole domain and the local regions. As a result of analysis on the test examples, it is found that the stress field in the local regions are approximated to those in the whole domain within a few iterations which have satisfied the original finite element equilibrium equation. In addition, it is found that the local stress field are by far better approximated to the exact stress field than the displacement-based stress field with the reduction of the finite-element mesh-size.

• Journal of Advanced Marine Engineering and Technology
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• v.35 no.8
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• pp.1070-1077
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• 2011

This study includes field test results for performance evaluation of a tubular turbine in marine small hydro power plant. Minimum output power of the tested turbine generator is examined with using of the measured effective head, output power and efficiency. For the rated and maximum output power tests, corrected values from the result of turbine model test are used for the performance evaluation, because experimental conditions of field test at the rated and maximum output powers are restricted correctly. Performance of the test turbine shows good conformance with the suggested guarantee values of output power and efficiency at the measured points of minimum, rated and maximum output power.

• Journal of Energy Engineering
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• v.8 no.2
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• pp.233-241
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• 1999

A large-scale hot water production system using a natural circulation loop was developed. A computer simulation program was developed to design and evaluate thermal performance of the natural circulation system for hot water production. An experimental apparatus was set up and was tested against various conditions to exhibit a stable operating region of the natural circulation loop. When the system was a stable state for heating rate (695 ㎾) and feed water was circulated at 0.3 $\ell$/s constantly. A unstable state was checked by experiment and that time flow rate was oscillated with 0.4∼0.6 $\ell$/s. The result showed that the program can predict the thermal performance of the large-scale hot water system using the natural circulation loop and can be utilized to design the system.

• Journal of Engineering Education Research
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• v.13 no.5
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• pp.25-28
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• 2010

The objective of this project is to cultivate interest among junior high school students toward Science & Technology. Six simple experiments will be introduced to the participants (junior high school students) of this project which is focusing on the basic principles of engineering including law of motion, free-fall, force, energy, friction and work. Our student team has been assigned to design six set of experiment according to the principles. The experiments are easy to understand and simple to assemble by the students of age 13 to 15. Experimental manuals were written by the members using simple words complete with figure so that all the participants can understand the procedure of each experiment. In order to make sure the manuals are practically working, the experiment sets were tested and the results were compared with actual theory. As a result, we believe that the experiments can be done by the students within less supervision. The students are able to set up the experiments by using some simple equipment around them. By doing this experiments, we can further our understanding and explain better the principles of energy, force and work.

• Journal of the Korean Society of Clothing and Textiles
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• v.25 no.3
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• pp.650-661
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• 2001

The purpose of this study is to suggest a guidance to select proper muslin through investigating fabric characteristics. The structural and physical properties of muslin and top fabric samples were tested by KES-FB system and other testers. And in order to examine the relation between fabric characteristics and the shape of garments, wearing tests were done with jackets made of those samples. As a result, bending rigidity(B), bending hysteresis(2HB), shear stiffness(G), shear hysteresis at=0.5(2HG), shear hysteresis at=5(2HG5), stiffness, cloth count/5cm, weight, thickness were extracted as the key factors affecting the appearance of garments. To have similar appearance, all of these should be counted. After standardizing, we calculate the variance between top cloth and muslin. And from this we could get the range that the proper muslin should be included. The ranges were as follows: Bending rigidity(B): within 0.024g.$\textrm{cm}^2$/cm(0.3$\sigma$); Shear stiffness(G): within 2.21g/cm.degree(1.3$\sigma$) Weight: within 9.33mg/$\textrm{cm}^2$(18$\sigma$); Thickness: within 0.20mm(1.8$\sigma$)

• Journal of Korea Society of Digital Industry and Information Management
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• v.6 no.3
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• pp.211-219
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• 2010

This paper designs the dynamic symbol automatic trading system in Korean option market. This system is based on Multichart program which is convenient and efficient system trading tool. But the Multichart has an important restriction which has only one constant symbol per chart. This restriction causes very useful strategies impossible. The proposed design uses global variables, signal chart selection and position order exchange. So an automatic trading system with dynamic symbol works on Multichart program. To verify the proposed system, BS(Buythensell)-SB(Sellthenbuy) strategies are tested which uses the change of open-interest of stock index futures within a day. These strategies buy both call and put option in ATM at start candle and liquidate all at 12 o'clock and then sell both call and put option in ATM at 12 o'clock and also liquidate all at 14:40. From 23 March 2009 to 31 May 2010, 301-trading days, is adopted for experiment. As a result, the average daily profit rate of this simple strategies riches 1.09%. This profit rate is up to eight times of commision price which is 0.15 % per option trade. If the method which raises the profitable rate of wining trade or lower commission than 0.15% is found, these strategies make fascinated lossless trading system which is based on the proposed dynamic symbol automatic trading system.