• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.48 no.12
• /
• pp.1498-1506
• /
• 1999

In this paper, a hybridization of Evolutionary Strategy (ES) and a Two-Phase Neural Network(TPNN) is applied to the optimal environmental and economic operation. As the evolutionary computation, ES is to search for the global optimum based on natural selection and genetics but it shows a defect of reducing the convergence rate in the latter part of search, and often does not search the exact solution. Also, neural network theory as a local search technique can be used to search a more exact solution. But it also has the defect that a solution frequently sticks to the local region. So, new algorithm is presented as hybrid methods by combining merits of two methods. The hybrid algorithm has been tested on Emission Constrained Economic Dispatch (ECED) problem and Weighted Emission Economic Dispatch (WEED) problem for optimal environmental and economic operation. The result indicated that the hybrid approach can outperform the other computational efficiency and accuracy.

• 한국생물공학회:학술대회논문집
• /
• 2000.04a
• /
• pp.382-385
• /
• 2000

This study tested for biological treatment of dye wastewater using isolated microbes taken from dye wastewater and commercial carriers. In the result, single strain of mocrobe achieved about 45% color removal efficiency in average. When two strains of microbes applied to the treatment, color removal efficiency was increased up to 85%. The carriers had optimal concentration as 15%

• 한국생물공학회:학술대회논문집
• /
• 2001.11a
• /
• pp.422-425
• /
• 2001

For isolating and identifying Bifidobacterium spp. originating from Korea, feces were sampled from healthy Korean infants nursery school and postpartum care center. Through the use of gram staining and microscopic examination for cell morphology, 87 bacterial strains presumed to be the Bifidobacterium strains were isolated from 59 Koreans. To identify the Bifidobacterium strains at the genus level, these bacteria were then analyzed using the TLC method. As a result, 29 of the isolated strains were confirmed as members of the genus Bifidobacterium. 29 Bifidobacterium strains were tested acid, bile salts and oxygen tolerance and investigated antioxidative effect specially. And determined the superiority of 5 strains out of 29 Bifidobacterium strains. Finally, the selected bifidobacterium was identified with using designed 16S-ITS rDNA primer.

• 한국생물공학회:학술대회논문집
• /
• 2001.11a
• /
• pp.525-528
• /
• 2001

The purpose of this study is to looking for the optimal condition of methane production enhancement. The conditions tested for increasing methane production were temperature. pH. and various carbon sources including methanol. formic acid. sodium acetate. succinic acid. and glucose. As a result, optimal temperature was 55 .C and optimal pH was around neutral condition. And methanol seemed to be best carbon source which can drastically increase methane production.

• Proceedings of the Korea Concrete Institute Conference
• /
• 1999.10a
• /
• pp.139-142
• /
• 1999

The purpose of this experimental research is to investigate the mechanical properties of ordinary strength and high strength concrete containing waste glass powder. For this purpose, after production of concrete containing waste glass powder for different unit weight of binder and placement ratio of waste glass powder, optimum mixing proportions of them was determined, and then mechanical properties such as static modulus of elasticity as well as compressive, tensile and flexural strength were tested and analyzed for concrete produced according to optimum mixing proportions. As a result, the concrete containing waste glass powder has as excellent workability and strength, it's strengths are analogus to those of silica fume, it's workability is somewhat better than that of silica fume.

• Proceedings of the Korea Concrete Institute Conference
• /
• 1999.10a
• /
• pp.589-592
• /
• 1999

This paper is experimental study on the flexural strength and ductility capacity of reinforced high-strength concrete beams using fly ash artificial lightweight concrete beams and five reinforced high-strength normal concrete beams with different tensile reinforcement ratio were tested to investigate their behavior. Test result show that the ratio of flexural strength between experimetal results and those by ACI code decrease as the compressive strength of concrete increase. Also, The reinforced concrete beams behave more brittly than those with equal reinforcement ratio($\rho$/$\rho$b) as the compressive strength of concrete increase.

• Journal of Advanced Marine Engineering and Technology
• /
• v.25 no.5
• /
• pp.1091-1097
• /
• 2001

A numerical investigation was performed to determine the effect of airfoil on the optimum flap height using NACA 00XX and 44XX airfoils. The six flaps which have 0.5% chord height difference were selected . A Navier-Stokes code, FLUENT, was used to calculate the flow field of the airfoil. The code was first tested as a benchmark by modelling flow around a NACA 4412 airfoil. Predictions of local pressure coefficients are found to be in good agreement with the result of the experimental results. For every NACA 00XX and 44XX airfoil, flap heights ranging from 0.0% to 2.5% chord were changed by 0.5% chord interval and their effects were also studied. Representative results from each case are presented graphically and discussed. It is conclued that this initial approach gives an idea for the future development of the wind turbine optimum design.

• Proceedings of the Korean Society For Composite Materials Conference
• /
• 2001.05a
• /
• pp.163-167
• /
• 2001

A two-dimensional progressive failure analysis method is presented for the strength characterization of the composite joints under pin loading. The eight-nodes laminated she]1 element is utilized based on the updated Lagrangian formulation. The criteria by Yamada-Sun, Tsai-Wu, and the maximum stress are used for the failure estimation. The stiffness of failed layer is degraded by the complete unloading method. No factor depending on test is included in the finite element analysis except for the material strength and stiffness. Total 20 plate specimens with and without hole are tested to validate the finite element prediction. The Tsai-Wu failure criterion most conservatively estimates the strength of laminate, and the maximum stress criterion yields the highest strength because it does not consider the coupling of the failure modes. The strength by Yamada-Sun method neglecting the matrix failure effect are located between other two methods and shows best agreement with test result for laminate with hole.

• Food Science and Preservation
• /
• v.4 no.3
• /
• pp.311-315
• /
• 1997

Proximate compositions of black rice and antioxidative effects of its methanol extract on refined perilla oil were investigated. Black rice seeds were composed of water 12.4%, crude protein 7.9%, crude fat 2.2%, crude fiber 1.0%, ash 1.4% and N-free extract 75.1%. The hexane and 80% methanol fractions in yields were higher than 80% ethanol and chloroform. In AOM(active oxygen method) test, antioxidative effects of black rice added to the refined perilla oil was increased with dose-dependent fashion in concentration of the black rice extracts. Among several extracts tested, 80% aqueous methanol extract showed the highest antioxidative activity, followed by hexane, chloroform, in that order. The peroxide value and TBA value for their antioxidation stability were also lower than that of control. This result was similar to that of AOM test.

• Proceedings of the Korean Institute of Intelligent Systems Conference
• /
• 2003.09a
• /
• pp.179-182
• /
• 2003

This paper proposes an adaptive hybrid genetic algorithm (aHGA) for effectively solving the complex reliability optimization problems. The proposed aHGA uses a loca1 search technique and an adaptive scheme for respectively constructing hybrid algorithm and adaptive ability. For more various comparisons with the proposed adaptive algorithm, other aHGAs with conventional adaptive schemes are considered. These aHGAs are tested and analyzed using two complex reliability optimization problems. Numerical result shows that the proposed aHGA outperforms the other competing aHGAs.