• The Transactions of the Korean Institute of Electrical Engineers A
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• v.49 no.6
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• pp.272-279
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• 2000

This paper describes a controller design and dynamic performance analysis of UPFC based on 3-level inverters. Major attention is focused on the controller design for both shunt and series inverters, including regulator design for the dc link voltage sharing across the dc capacitors. An energy-based approach was investigated for effectively designing the controller. A detailed UPFC model has been developed with EMTP using 24-pulse 3-level inverters to verify this approach. Simulation results about dynamic performance of UPFC confirm effects for increasing transmission capacity and damping low-frequency oscillation. The developed simulation model would be very effective to analyze the dynamic performance of UPFC.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1994.11a
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• pp.40-45
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• 1994

The TCAD(Technology Computer Aided Design) software tool is a popular name to be able to simulate the semiconductor process and device circuit. We have developed a two-dimensional TCAD software tool included an editor, parser, each process unit, and 2D, 3D graphic routine that is Integrated Environment. The initial grid for numerical analysis is automatically generated with the geometric series that use the user default(given) line and position separated with grid interval and the nodes corresponding to each mesh point stoic the all the possible attribute. Also, we made a data structure called PIF for input or output. Methods of ion implantation in this paper arc Monte Carlo, Gaussian Pearson and Dual-Pearson. Analytical model such as Gaussian, Pearson and Dual-Pearson were considered the multilayer structure and two-dimensional tilted implantation. We simuttaneously calculated the continuity equation of impurity and point defect in diffusion simulation. Oxidation process was simulated by analytical ERFC(Complementary Error Function) model for local oxidation.

• Proceedings of the KIEE Conference
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• 2002.11c
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• pp.333-336
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• 2002

In many cases, fuzzy modeling has a defect that the design procedure cannot be theoretically justified. To overcome this difficulty, we suggest a new design method for fuzzy model by combining genetic algorithm(GA) and mush set theory. GA, which has the advantages is optimization, and rule base. However, it is some what time consuming, so are introduce rough set theory to the rule reduction procedure. As a result, the decrease of learning time and the considerable rate of rule reduction is achieved without loss of useful information. The preposed algorithm is composed of three stages; First stage is quasi-optimization of fuzzy model using GA(coarse tuning). Next the obtained rule base is reduced by rough set concept(rule reduction). Finally we perform re-optimization of the membership functions by GA(fine tuning). To check the effectiveness of the suggested algorithm, examples for time series prediction are examined.

• International Journal of Aeronautical and Space Sciences
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• v.2 no.1
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• pp.28-43
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• 2001

Developed in these two series of paper is a complex dynamic model representing the motion of aircraft on the ground and a computer program for numerical simulation. The first part of paper presents the theoretical derivation of equations of motion of the landing gear system based on the physical principle. Developed model is 'structured' in the sense that the undercarriage system is regarded as an assembly of strut, tire, and wheel, where each component is modeled by a separate module. These modules are linked with two external modules-the aircraft and the runway characteristics-to carry out dynamic analysis and numerical simulation of the aircraft motion on the ground. Three sets of coordinate system associated with strut, wheel/tire and runway are defined, and external loads to each component and response characteristics are examined. Lagrangian formulation is used to derive the undercarriage equations of motion relative to the moving aircraft, and the resultant forces and moments from the undercarriage are transformed to aircraft body axes.

• Korean Management Science Review
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• v.18 no.2
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• pp.39-60
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• 2001

This Paper deals with a collaborative decision making procedure of web-based DSS for supply chain management (SCM). The seemingly autonomous DSS dedicated to each of mutually exclusive prob1em domains forms a communication network and cooperates each other for better SCM decision making. We a1so propose a hub-spoke information sharing model for the DSS network. In the hub-spoke model, an information hub at the center facilitates information exchange between DSS\\`s and controls the conversations defined by the series of XML messages between agents of DSS. A product ordering scenario where supply decision is triggered upon customer order is used to demonstrate the SCM decision procedure through a collaboration of the web-based DSS.

• Journal of Biomedical Engineering Research
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• v.5 no.1
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• pp.9-14
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• 1984

The asymptotic solution using the Tailor series has been given explicit form for the solute concentration and overall solute removal in hemodiafilter using one dimensional model. The numerical solutions have been calculated within 0.001% error by the Romberg integration method. Compared with the numerical solutions, the oneterm asymptotic solutions were found to be within 3% error for the condition > 3.0 and three-terms asymtotic solutions were required for the condition >0.7 where denotes measure of convection over diffusional transport and a the ratio of blood flow rate over dialysate flow rate.

• Tunnel and Underground Space
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• v.15 no.6 s.59
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• pp.400-410
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• 2005

During excavation of shallow tunnels in soft ground, failure mechanism around the tunnel face have major influence on the stability of tunnels. In this paper, a series of laboratory tests under plane strain condition on the small scale of a shallow tunnel considering unsupported tunnel length has been performed. The results have shown that tunnel failure mechanism changes from failure mode 1 to failure mode 2 as unsupported tunnel length increases. By comparing the experimental and the numerical results, the loosening pressure for the shallow tunnel and progressive failure have been investigated.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2000.11a
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• pp.281-285
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• 2000

The effect of the presence of dissolved organic matters(DOM) on the binding of phenanthrene to cetylpyridinium chloride(CPC) coated sand was investigated. The distribution coefficient of phenanthrene increased with increase of sufactant coverage, and decreased with the presence of dissolved organic matters except for the 1.600mg/g coverage case. Both Aldrich humic acid and extracted dissolved organic matter showed the similar tendency. For the quantification of the overall distribution coefficient, this study presented mass distribution model and estimated the sorption equilibrium coefficients of hydrophobic organic compounds(HOCs) in multi system. The suggested model combined a series of sorption equilibrium relationships including the adsorption of DOMs on sorbents, the binding between HOCs and DOMs, and the sorption of HOCs on sorbents with or without DOMs.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.11
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• pp.4556-4572
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• 2015

Dynamic texture (DT) recognition is a challenging problem in numerous applications. In this study, we propose a new algorithm for DT recognition based on group sparsity structure in conjunction with chaotic feature vector. Bag-of-words model is used to represent each video as a histogram of the chaotic feature vector, which is proposed to capture self-similarity property of the pixel intensity series. The recognition problem is then cast to a group sparsity model, which can be efficiently optimized through alternating direction method of multiplier algorithm. Experimental results show that the proposed method exhibited the best performance among several well-known DT modeling techniques.

• Magazine of the Korean Society of Agricultural Engineers
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• v.42 no.5
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• pp.78-83
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• 2000

When a sea-dike is constructed on soft soils, it is much difficult to calculate ground deformation caused by forced displacements. In this study , a series of laboratory model tests have been performed to investigate the ground deformation under a constructed sea-dike on soft soils. Construction sequence of sea-dike embankment was assumed such as constructed by quarry first and followed by soils adjacent to quarry embankment. as test data and displacement in subsoils have been analyzed, it seems that deformation is caused by general shear failure. the shape of ground deformation caused by forced displacements was well defined be parabola . Upon comparing profiles and depth of forced displacement from the model test to those based on stress-baring capacity method commonly used, it has been found that deformation prediction using stress-bearing capacity method was not exact at the edge of loading.