• Advances in Traditional Medicine
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• v.4 no.2
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• pp.82-86
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• 2004

The efficacy of Kohl-Chikni Dawa (KCD), a compound ophthalmic formulation of Unani medicine, to control cataract development was explored in rats fed 25% galactose with the diet for 6 months. When one drop of 3% KCD solution was applied (once and twice daily) in both eyes for 6 months in galactose-fed rats, a significant reduction of lens opacification was noticed. The morphological changes of the lenses were observed every month by slit-lamp biomicroscope. These results suggest that the local application of 3% KCD solution possesses anticataract effect in galactose-fed rats.

• Proceedings of the KIEE Conference
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• 2003.07a
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• pp.403-405
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• 2003

In this paper, we applied a chaos search method for feeder reconfiguration problem in unbalanced distribution system. Chaos method, in optimization problem, searches the global optimal solution on the regularity of chaotic motions and more easily escapes from local or near optimal solution than stochastic optimization algorithms. The chaos search method applied to the IEEE 13 unbalanced test feeder systems, and the test results indicate that it is able to determine appropriate switching options for global optimum configuration.

• Industrial Engineering and Management Systems
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• v.8 no.1
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• pp.29-36
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• 2009

We present two local-search based metaheuristics for the multi-source capacitated facility location problem. In such a problem, each customer's demand can be supplied by one or more facilities. The problem is NP-hard and the number of locations in the optimal solution is unknown. To keep the search process effective, the proposed methods adopt the following features: (1) a multi-exchange neighborhood structure, (2) a tabu list that keeps track of recently visited solutions, and (3) a multi-start to enhance the diversified search paths. The transportation simplex method is applied in an efficient manner to obtain the optimal solutions to neighbors of the current solution under the algorithm framework. Two in-and-out selection rules are also proposed in the algorithms with the purpose of finding promising solutions in a short computational time. Our computational results for some of the benchmark instances, as well as some instances generated using a method in the literature, have demonstrated the effectiveness of this approach.

• Journal of the Korean Society of Marine Environment & Safety
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• v.3 no.2
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• pp.93-103
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• 1997

This paper develops a new heuristic, the Excursion Algorithm(EA), for constructing optimal designs for the experiments related with marine environment. The proposed EA consists of three parts: 1) construction of an initial feasible solution, 2) excursions over a bounded region, and 3) stopping rules. It is the second part that distinguishes the EA from the other existing heuristic methods. It turns out that excursions over a bounded feasible and/or infeasible region is effective in alleviating the risks of being trapped at a local optimum. Since this problem is formulated for the first time thesis, other heuristic algorithms do not exist. Therefore, global optimal solutions are obtained by complete enumeration for some cases, and the performance of the EA is evaluated in terms of solution quality. Computational results show that the proposed EA is effective in finding good(or, in many cases, global) solutions to the constrained optimal experimental design problems.

• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.811-813
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• 2008

To see the effect of magnesium on adhesion to natural zeolites, a series of batch tests were performed in this research. Mixed bacteria were sampled from the digestion tank at a local sewage treatment plant in Seoul. Magnesium-zeolites were synthesized by mixing natural zeolites with 0.096 M, 0.24 M, and 0.48 M of MgCl2 solution. For comparison, manganese and trivalent ferric zeolites were also prepared. Two grams of 0.2 mm $\sim$ 0.3 mm sized zeolites(non-treated, Mg, Mn and Fe(III) treated zeolites) and 20 mL of water were mixed in a Corex 25 mL tube. Five milliliters of culture solution including bacteria was added to the tube. The tubes were equilibrated in a shaking incubator at mesophilic temperature $(30{\pm}2^{\circ}C)$. The bacterial concentrations were measured with a Microluminometer (New Horizons 3550i) and total organic carbon (TOC) spectrophotometer (Multi NC-3100).

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.425-426
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• 2007

In power systems operation, state estimation takes an important role in security control. For the state estimation problem, conventional optimization algorithm, such as weighted least squares (WLS) method, has been widely used. But these algorithms have disadvantages of converging local optimal solution. In these days, a modern heuristic optimization methods such as Particle Swarm Optimization (PSO), are introducing to overcome the problems of classical optimization. In this paper, we suggested parallel particle swarm optimization (PPSO) to search an optimal solution of state estimation in power systems. To show the usefulness of the proposed method over the conventional PSO, proposed method is applied on the IEEE-57 bus system.

• Bulletin of the Korean Mathematical Society
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• v.53 no.2
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• pp.531-540
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• 2016

In this work, we introduce the complete Riemannian manifold $\mathbb{F}_3$ which is a three-dimensional real vector space endowed with a conformally flat metric that is a solution of the Einstein equation. We obtain a second order nonlinear ordinary differential equation that characterizes the helicoidal minimal surfaces in $\mathbb{F}_3$. We show that the helicoid is a complete minimal surface in $\mathbb{F}_3$. Moreover we obtain a local solution of this differential equation which is a two-parameter family of functions ${\lambda}_h,K_2$ explicitly given by an integral and defined on an open interval. Consequently, we show that the helicoidal motion applied on the curve defined from ${\lambda}_h,K_2$ gives a two-parameter family of helicoidal minimal surfaces in $\mathbb{F}_3$.

• Journal of the Korea institute for structural maintenance and inspection
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• v.3 no.3
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• pp.167-176
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• 1999

This paper is concerned with the damage detection of existing 2 and 3-dimensional truss structures based on free vibration equation and extended Kalman filter. The local damage is characterized in terms of the stiffness degradation of damaged members. As the observed data, the natural frequencies and mode shapes of damaged truss structure model are adopted. Both location and stiffness of damaged parts of members in truss structures can be estimated by the proposed inverse solution procedure. The applicability and effectiveness of proposed inverse solution procedure are demonstrated through the numerical examples.

• Steel and Composite Structures
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• v.24 no.6
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• pp.697-709
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• 2017

The current study addresses the local buckling analysis of an infinite thin rectangular symmetrically laminated composite plate restrained by a tensionless Winkler foundation and subjected to uniform in-plane shear loading. An analytic method (i.e., one-dimensional mathematical method) is used to achieve the analytical solution estimate of the contact buckling coefficient. In addition, to study the effect of ply angle and foundation stiffness on the critical buckling coefficients for the laminated composite plates, the parametric studies are implemented. Moreover, the convergence for finite element (FE) mesh is analysed, and then the examples in the parametric study are validated by the FE analysis. The results show that the FE analysis has a good agreement with the analytical solutions. Finally, an example with the analytical solution and FE analysis is presented to demonstrate the availability and feasibility of the presented analytical method.

• Bulletin of the Korean Chemical Society
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• v.20 no.6
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• pp.715-719
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• 1999

The incorporation of cobalt into mesoporous molecular sieves MCM-41 and MCM-48 was carried out. Co-PO/MCM41 and Co-PO/MCM48 were prepared using Co(II) acetate solution adjusted to pH = 3.0 with phosphoric acid by the incipient wetness method. Photoacoustic spectroscopy (PAS) was used to study the local environments of Co(II) incorporated into mesopores. The band around 500 nm in PAS of as-prepared Co-PO/MCM41 and Co-PO/MCM48 with Co(II) acetate solution was changed to triplet bands around 600 nm. This could be assigned to the 4 A2(F)-> 4T1(P) transition of Co(II) surrounded tetrahedrally by oxygen ions after calcination. It may be attributable to that the octahedral cobalt species containing phosphate ligands in coordination sphere reacting with framework's silanol groups to be dispersed atomically onto the surface of mesoporous molecular sieves as a tetrahedral species. This is unlike that the Co in Co-Cl/MCM41 and direct-synthesized Co-MCM41 transforms to Co oxide phase upon calcination. Co-PO/MCM41 and Co-PO/MCM48 were stable while treated with water.