• Water Engineering Research
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• v.1 no.1
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• pp.63-74
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• 2000

This paper presents a two- phase search scheme for optimal pipe expansion of expansion of existing water distribution systems. In pipe network problems, link flows affect the total cost of the system because the link flows are not uniquely determined for various pipe diameters. The two-phase search scheme based on stochastic optimization scheme is suggested to determine the optimal link flows which make the optimal design of existing pipe network. A sample pipe network is employed to test the proposed method. Once the best tree network is obtained, the link flows are perturbed to find a near global optimum over the whole feasible region. It should be noted that in the perturbation stage the loop flows obtained form the sample existing network are employed as the initial loop flows of the proposed method. It has been also found that the relationship of cost-hydraulic gradient for pipe expansion of existing network affects the total cost of the sample network. The results show that the proposed method can yield a lower cost design than the conventional design method and that the proposed method can be efficiently used to design the pipe expansion of existing water distribution systems.

• Journal of applied mathematics & informatics
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• v.29 no.3_4
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• pp.813-829
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• 2011

In this article, we present a numerical scheme for solving singularly perturbed (i.e. highest -order derivative term multiplied by small parameter) Burgers-Huxley equation with appropriate initial and boundary conditions. Most of the traditional methods fail to capture the effect of layer behavior when small parameter tends to zero. The presence of perturbation parameter and nonlinearity in the problem leads to severe difficulties in the solution approximation. To overcome such difficulties the present numerical scheme is constructed. In construction of the numerical scheme, the first step is the dicretization of the time variable using forward difference formula with constant step length. Then, the resulting non linear singularly perturbed semidiscrete problem is linearized using quasi-linearization process. Finally, differential quadrature method is used for space discretization. The error estimate and convergence of the numerical scheme is discussed. A set of numerical experiment is carried out in support of the developed scheme.

• Communications of the Korean Mathematical Society
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• v.31 no.2
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• pp.395-414
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• 2016

In this work, we study on subdivision schemes reproducing polynomials and build a symmetric subdivision scheme reproducing polynomials of a certain predetermined degree, which is a slight variant of the family of Deslauries-Dubic interpolatory ones. Related to polynomial reproduction, a necessary and sufficient condition for a subdivision scheme to reproduce polynomials of degree L was recently established under the assumption of non-singularity of subdivision schemes. In case of stepwise polynomial reproduction, we give a characterization for a subdivision scheme to reproduce stepwise all polynomials of degree ${\leq}L$ without the assumption of non-singularity. This characterization shows that we can investigate the polynomial reproduction property only by checking the odd and even masks of the subdivision scheme. The minimal-support condition being relaxed, we present explicitly a general formula for the mask of (2n + 4)-point symmetric subdivision scheme with two parameters that reproduces all polynomials of degree ${\leq}2n+1$. The uniqueness of such a symmetric subdivision scheme is proved, provided the two parameters are given arbitrarily. By varying the values of the parameters, this scheme is shown to become various other well known subdivision schemes, ranging from interpolatory to approximating.

• Journal of the Korea Safety Management & Science
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• v.10 no.3
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• pp.29-33
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• 2008

According to statistics released by the Ministry of Labor for the past 6 years, work-related accidents in the construction industry have been on the continued increase, resulting in social and economic losses that are difficult to determine at an exact amount. However, the number will likely get much bigger if unreported cases are included, considering the fact that the aforementioned statistics are based soley on the applications filed with Korea Workers' Compensation and Welfare Service. The practice of businesses choosing not to report and dealing with industrial accidents in an unauthorized manner is defined as "concealment of industrial accident". The reason the employers tend to engage in the concealment practice even at their huge cost is a "pre-qualification" scheme for the applicants in the government procurement process. Under the pre-qualification scheme, the applicants with a high rate of industrial accidents receive a low grade and become less attractive candidates in the procurement process, thus losing an opportunity to win a contract. Such failure relates directly to the fate of business organizations, to survive or not. That is why they are making all-out efforts to obtain a high grade in the pre-qualification evaluation. With regard to the accident-concealment problem, the following can be mentioned as preventive measures: (1) To exclude a rate of industrial accidents from the pre-qualification scheme; (2) To strengthen the institution of imposing penalties on the occurrence of industrial accidents; (3) To introduce private insurance system to the current industrial accident compensation insurance; and (4) To give non-recognition treatment to industrial accidents that were not reported upon occurrence. In conclusion, the concealment problem can be resolved if the aforementioned measures are to be taken continuously along with corrective measures against institutional deficiencies.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.11
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• pp.5202-5207
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• 2011

A temperature control system is very important part in many industrial applications. Typical development procedures for temperature control system consist of several stages such as conceptual system design, construction of physical system, controller design based on the mathematical model for the system, and performance test. Since the mathematical model is usually obtained with the aid of system identification technique based on repeated experiments after construction of the physical system, the above procedures require very large amount of time and cost. It takes also large amount of time in the controller design and performance test procedures. In this paper, a virtual development scheme, which can predict the performance of the temperature control system prior to construction of physical system, for rapid validation of the initial system design is proposed. The effectiveness of the proposed scheme is shown by using SISO (Single Input Single Output) example.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2004.11a
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• pp.380-383
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• 2004

Recently, by the growth of IT industry, the domestic construction is tried to spread with IT on the whole phases: 1)an, design, order, construction, and maintenance. On this, in the construction industry, is accelerated effort of the introduction of PMIS, it has various types of PMIS applied which is developed alone by large construction company and serviced with web-hosting by ASP corporation. In this study, through the analysis of PMIS which has applied on the subway construction in the D city, try to propose the improvement proposals and put out realistic problems. Therefore that analysis about needs of the order and operation of the phases, Domestic PMIS cases and International PMIS technique position have to consider and, the system is analyzed to needs of the order, design scheme, and utilization. On the basis of this result, the improvement proposals is proposed into the case of the contract, the system, the operation, the management and the contact of the external system.

• Journal of Korean Society for Geospatial Information Science
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• v.16 no.4
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• pp.89-99
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• 2008

In Korea, currently 10 local governments have completed the construction of the 3D Land Geospatial Information, since the pilot project started in 2004 and many other local governments are additionally constructing the 3D Land Geospatial Information. Technical Guidance for the 3D Land Geospatial Information has made out the construction methodology and concept of the ordinances in 2006 by the basis of the research results of the pilot project for the 3D Geospatial Information construction in 2005. But the result that applied the existing 3D Land Geospatial Information of the local governments, many problems rearing up on the methods and expression accuracy of the 3D Land Geospatial Information. This research analyzed and derived problems of established guideline for the zero-defects construction of the 3D Land Geospatial Information and it is aim at the present standardized criterion of the reestablished and method of the 3D Geospatial Information construction items. Improvement scheme of the 3D Land Geospatial Information is considered to be contribute to the standardized good quality of 3D Land Geospatial Information construction and its application.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.27 no.6
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• pp.406-418
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• 2015

The present modified FUNWAVE-TVD model, which is a modification to its previous version 2.1, is applied to solitary wave propagation and is tested against the experiments of Vincent and Briggs(1989) and Luth et al.(1994). The eddy viscosity breaking scheme is used for comparison with the existing study in the case of breaking experiment. The symmetry of wave-induced current is maintained when the modified model is employed to Vincent and Briggs(1989) breaking experiment, but the symmetry of wave-induced current in previous model is not maintained. A better agreement with the breaking experimental data is obtained in the modified model using eddy viscosity breaking scheme than the shock capturing breaking scheme using nonlinear shallow water equation. For comparison with the schemes in the model, the fourth order MUSCL-TVD scheme by Erduran et al.(2005) and the third order MUSCL-TVD scheme using minmod limiter is applied, and the numerical solutions of solitary wave are compared.

• Korean Institute of Interior Design Journal
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• v.21 no.4
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• pp.190-199
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• 2012

In this era of information, the public library takes a important role in the local community. In several years, public libraries have been proliferated in our society. However, there have not been specific planning standards of space size for construction of public library. The situation has lead the local governments to the need of consulting for the construction and management of library in search of appropriate guideline. The research paper focuses on the result of consulting support project for construction and management of public library. It examines total 11 libraries which were consulted from 2009 to 2011. It examines the configurational differences between the first scheme from the local government and the final scheme after the consulting, and the percentages of gross areas of each parts of library, reference and reading area, office area, education and cultural area, and public common use area. The analysis concludes that reference and reading area increased by 6.4% from 34.1% to 40.5%, and public common use area reduced by 6.1% from 30.2% to 24.1%, which represents a certain tendency of the configuration ratio of the each parts. Thus, the paper could be a starting point of establishing planning standard of space size for public library.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.09a
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• pp.198-199
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• 2005