• Korean Journal of Construction Engineering and Management
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• v.2 no.4 s.8
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• pp.144-156
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• 2001

This study aims at improving the limitations of current construction processes. Previous solutions to improve construction processes have been focused on the improvement of local processes. This paper proposes a method to improve global effectiveness of construction processes through ascertainment of communication among the process participants. This paper provides two case studies: Deck plate installation processes and Duct installation processes. The case study illustrates a way to improve global effectiveness by incorporating downstream participants such as specialty contractors in upstream construction processes such as design and planning.

• International Commerce and Information Review
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• v.4 no.2
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• pp.97-119
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• 2002

This research purposes on comparing some e-trailing models in character and presenting the obstacles of e-trailing activation and the solutions, e-trailing models this research has studied are 1) Bolero, 2) TradeCard, 3) BeXcom, 4) Identrus, and 5) TEDI etc. Comparing characteristic points of the e-trading models are as follows ; 1) Access ways as a global e-trading model, 2) Structural characteristic, 3) Functional characteristic, 4) Role as a global e-trading model, 5) Legal issues, 6) Application issues in practice, 7) Security issues for Technology.

• Proceedings of the KSME Conference
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• 2001.11a
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• pp.324-329
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• 2001

A novel method for non-matching interfaces on the boundaries of the finite elements in partitioned domains is presented by introducing interface elements in this paper. The interface element method (IEM) satisfies the continuity conditions exactly through interfaces without recourse to the Lagrange multiplier technique. The moving least square (MLS) approximation in the present study is implemented to construct the shape functions of the interface elements. Alignment of the boundaries of sub-domains in the MLS approximation and integration domains provides a consistent numerical integration due to one form of rational functions in an integration domain. The compatibility of displacements on the boundaries of the finite elements and the interface elements is always preserved in this method, and the completeness of the shape functions of the interface elements guarantees the convergence of numerical solutions. The numerical examples show that the interface element method is a useful tool for the analysis of a partitioned system and for a global-local analysis.

• Ocean Systems Engineering
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• v.1 no.2
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• pp.171-194
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• 2011

A method to design a boundary controller for global stabilization of three-dimensional nonlinear dynamics of flexible marine risers is presented in this paper. Equations of motion of the risers are first developed in a vector form. The boundary controller at the top end of the risers is then designed based on Lyapunov's direct method. Proof of existence and uniqueness of the solutions of the closed loop control system is carried out by using the Galerkin approximation method. It is shown that when there are no environmental disturbances, the proposed boundary controller is able to force the riser to be globally exponentially stable at its equilibrium position. When there are environmental disturbances, the riser is stabilized in the neighborhood of its equilibrium position by the proposed boundary controller.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2006.04a
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• pp.373-380
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• 2006

Accurate and fast haptic simulations of deformable objects are desired in many applications such as medical virtual reality. In haptic interactions with a coarse model, the number of nodes near the haptic interaction region is too few to generate detailed deformation. Thus, local refinement techniques need to be developed. Many approaches have employed purely geometric subdivision schemes, but they are not proper in describing the deformation behavior of deformable objects. This paper presents a continuum mechanics-based finite element adaptive method to perform haptic interaction 'with a deformable object. This method superimposes a local fine mesh upon a global coarse model, which consists of the entire deformable object. The local mesh and the global mesh are coupled by the s-version finite element method (s-FEM), which is generally used to enhance accurate solutions near the target points even more. The s-FEM can demonstrate a reliable deformation to users in real-time.

• Proceedings of the KSME Conference
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• 2000.04a
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• pp.725-730
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• 2000

Genetic algorithms based on the theory of natural selection, have been applied to many different fields, and have proven to be relatively robust means to search for global optimum and handle discontinuous or even discrete data. Genetic algorithms are widely used for unconstrained optimization problems. However, their application to constrained optimization problems remains unsettled. The most prevalent technique for coping with infeasible solutions is to penalize a population member for constraint violation. But, the weighting of a penalty for a particular problem constraint is usually determined in the heuristic way. Therefore this paper proposes, the effective technique for handling constraints, the ranking penalty method and hybrid genetic algorithms. And this paper proposes dynamic mutation tate to maintain the diversity in population. The effectiveness of the proposed algorithm is tested on several test problems and results are discussed.

• Journal of applied mathematics & informatics
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• v.27 no.3_4
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• pp.749-755
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• 2009

In this paper, we investigate the invariant interval, periodic character, semicycle and global attractivity of all positive solutions of the equation $Y_{n+1}\;=\;\frac{p+qy_{n-k}}{1+y_n+ry_{n-k}}$, n = 0, 1, ..., where the parameters p, q, r and the initial conditions $y_{-k}$, ..., $y_{-1}$, $y_0$ are positive real numbers, k $\in$ {1, 2, 3, ...}. It is worth to mention that our results solve the open problem proposed by Kulenvic and Ladas in their monograph [Dynamics of Second Order Rational Difference Equations: with Open Problems and Conjectures, Chapman & Hall/CRC, Boca Raton, 2002]

• Proceedings of the KSME Conference
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• 2000.04b
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• pp.45-50
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• 2000

A numerical investigation is made of three-dimensional buoyant convection of a Boussinesq-fluid in a vertical cylinder. The top and bottom endwalls are thermally insulated. Flow is driven by the substantial azimuthal variations in thermal boundary conditions. Comprehensive numerical solutions to the Navier-Stokes equations are obtained. The representative Rayleigh number is large, thus, the overall flow pattern is of boundary layer-type. Three-dimensional (low characteristics are described. Specially, the global flow and the heat transfer features are delineated when the severity of azimuthal variation of sidewall temperature n, is intensified. Temperature and velocity fields on the meridional planes and the planes of constant height are presented. The global flow weakens as n becomes large. The pattern of the local Nusselt number on the surface of cylinder is similar regardless of n. The convective gain in heat transfer activities is reduced as n increases.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.614-615
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• 2005

The use of plastic substrates enables new applications, such as flexible display devices, and other flexible electronic devices, using low cost, roll-to-roll (R2R) fabrication technologies. One of the limitations of polymeric substrate in these applications is that oxygen and moisture rapidly diffuse through the material and subsequently degrade the electro-optical devices. GE Global Research (GEGR) has developed a plastic substrate technology comprised of a superior high-heat polycarbonate ($LEXAN^{(R)}$) substrate film and a unique transparent coating package that provides the ultrahigh barrier (UHB) to moisture and oxygen,chemical resistance to solvents used in device fabrications, and a high performance transparent conductor. This article describes the coating solutions for polycarbonate ($LEXAN^{(R)}$) films and its compatibility with OLED device fabrication processes.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2000.05a
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• pp.134-137
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• 2000

Genetic algorithms(GAs) have been widely used as a method to solve optimization problems. This is because GAs have simple and elegant tools with reproduction, crossover, and mutation to rapidly discover good solutions for difficult high-dimensional problems. They, however, do not guarantee the convergence of global optima in GA-hard problems such as deceptive problems. Therefore we proposed a Schema Co-Evolutionary Algorithm(SCEA) and derived extended schema 76988theorem from it. Using co-evolution between the first population made up of the candidates of solution and the second population consisting of a set of schemata, the SCEA works better and converges on global optima more rapidly than GAs. In this paper, we show advantages and efficiency of the SCEA by applying it to some problems.