• Geomechanics and Engineering
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• 제30권5호
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• pp.413-422
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• 2022

TBM is widely used in the construction of various underground projects in the current world, and has the unique advantages that cannot be compared with traditional excavation methods. However, due to the high cost of TBM, the damage is even greater when geological disasters such as collapse occur during excavation. At present, there is still a shortage of research on various types of risk prediction of TBM tunnel, and accurate and reliable risk prediction model is an important theoretical basis for timely risk avoidance during construction. In this paper, a prediction model is proposed to evaluate the risk level of tunnel collapse by establishing a reasonable risk index system, using analytic hierarchy process to determine the index weight, and using the normal cloud model theory. At the same time, the traditional analytic hierarchy process is improved and optimized to ensure the objectivity of the weight values of the indicators in the prediction process, and the qualitative indicators are quantified so that they can directly participate in the process of risk prediction calculation. Through the practical engineering application, the feasibility and accuracy of the method are verified, and further optimization can be analyzed and discussed.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제3권2호
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• pp.17-28
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• 1999

A new procedure of the boundary element method(BEM),say, singular BEM for the potential problems with singularities is presented. To obtain the numerical solution of which asymptotic behavior near the singularities is close to that of the analytic solution, we use particular elements on the boundary segments containing singularities. The Motz problem and the crack problem are taken as the typical examples, and numerical results of these cases show the efficiency of the present method.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1995년도 추계학술발표회논문집(1)
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• pp.29-34
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• 1995

The good features of the analytic function expansion nodal (AFEN) method are utilized to develop a practical scheme jot the multigroup diffusion problems, in combination with the polynomial expansion nodal (PEN) method. The thermal group fluxes exhibiting strong gradients are solved by the AFEN method[1-6], while the fast group fluxes that are smoother than the thermal group fuzes are solved by the PEN method[7-9]. The scheme is applied to a MOX-fuel loaded core with good results.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제21권1호
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• pp.17-28
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• 2017

A combined form of the modified Laplace Adomian decomposition method (LADM) is developed for the analytic treatment of the nonlinear Volterra-Fredholm integro differential equations. This method is effectively used to handle nonlinear integro differential equations of the first and the second kind. Finally, some examples will be examined to support the proposed analysis.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 B
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• pp.828-830
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• 2000

This paper describes BIEM(Boundary Integral Equation Method) for computation of three dimensional electric field distribution and numerical method that an equivalent charge density is unknown variable. After computing numerically the surface charge distribution. the distribution of both potential and electric field are obtained. Finally, this numerical method is applied to the concentric sphere and the coaxial cylindrical model and numerical result is compared to the analytic solution.

• 경영과학
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• 제11권3호
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• pp.129-151
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• 1994

This paper focuses on method of setting priorities for telecommunications Standardization in which usually includes prioritization, resource allocation, standardization schedule for each SWA is based on prioritization of SWAs. We mainly used the Analytic Hierarchy Process(AHP) and a modified Delphi technique as a method for planning process. Recently, rapid technology evolution in telecommunications fields increases the necessity of developing more and more new standards. Also increased complexity of technologies makes standards more complicated, more specified and more thick than the past ones. As a result, the number of SWAa(Standardization Work Areas) and SWIs(Standardization Work Iterms) is being increased continuously. Furthermore, rapid telecommunication environment changes such as deregulation, liberalization, privatization, regionalization, and globalization surrounding telecommunications standardization grows increasingly important. To cope with these challenges and to make the more efficient use of the limited standardization resources, i.e., time, financial, personal resources, we will suggest logical and rational approach that is a backbone of strategic plan for telecommunication standardization. The telecommunication standardization planning process involves a MCDM(Multi-Criteria Decision Making) process. The Analytic Hierarchy Process(AHP) is a kind of MCDM approach. Our method is based on a combination of a modified Delphi technique and an application of AHP(spreadsheet model). Analyzed data from Delphi technique is used as inputs to AHP. In addition we also focus on the technique how to combine group judgments and to handle a large number of comparisons.

• 한국안전학회지
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• 제32권6호
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• pp.104-109
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• 2017

As the ground subsidence occurred at the center of Seoul area in 2014, the ground subsidence phenomenon was emerged as a social issue in Korea. Even so far, national and local governments and related experts have been making a lot of efforts to prevent ground subsidence phenomenon, but it is still happening all over the country. In this study, we chose 9 influence factors on which ground subsidence and derived weights using AHP(Analytic Hierarchy Process) method for ground subsidence risk analysis. And we analyze the risk of subsidence in ${\bigcirc}{\bigcirc}$city using GIS(Geographic Information System) analysis method and evaluate the potential risk.

• 한국자동차공학회논문집
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• 제2권1호
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• pp.38-50
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• 1994

To improve the efficiency of internal combustion engines, it is necessary to understand mixed air-fuel in-cylinder flow processes accurately at intake and compression strokes. There is experimental and numerical methods to analyse in-cylinder flow process. In numerical method, standard $k-{\varepsilon}$ model with wall function was mostly adopted in in-cylinder flow process. But this type model was not efficiently predicted in the near wall region. Therefore in the present study, low Reynolds number $k-{\varepsilon}$ model was adopted near the cylinder wall and standard $k-{\varepsilon}$ model in other region. Also QUICK scheme was used for convective difference scheme. This study takes axisymmetric reciprocating model engine motored at 200rpm with a centrally located valve, incorporated 60 degree seat angie, and flat piston surface excluding inlet port. Because in-cylinder flow processes are undergoing unsteady and compressible, averaged cylinder pressure and inlet velocity at arbitrary crank angle are determined from thermodynamic analytic method and incylinder states at that crank angle are iteratively determined from the numerical analytic method.

• 한국농공학회논문집
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• 제49권3호
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• pp.63-68
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• 2007

The LRA(Logistic Regression Analysis) conducts a quantitative analysis by collecting a lot of samples and the AHP(Analytic Hierarchy Program) makes use of expert decision influenced by subjective judgment to a certain degree. This study is to suggest a combination method in mapping landslide hazard by giving equal weight for the result of LRA and AHP. Topographic factors(slope, aspect, elevation), soil dram, soil depth and land use were adopted to classify landslide hazard areas. The three methods(LRA, AHP, the combined approach) was applied to a $520km^2$ region located in the middle of South Korea which have occurred 39 landslides during 1999 and 2003. The suggested method showed 58.9% matching rate for the real landslide sites comparing with the classified areas of high-risk landslide While LRA and AHP Showed 46.1% and 48.7% matching rates respectively. Further studies are recommended to find the optimal combining weight of LRA and AHP with more landslide data.

• KIEAE Journal
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• 제13권6호
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• pp.113-120
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• 2013

Many countries over the world have taken many discussions and endeavors on environmental improvements of energy savings and greenhouse gas emission reductions for solving global climate change problems. In Korea, pre-considerations of environment-conscious factors in buildings have been taken to be critical with new constructions and renovation markets. In this situation, the Korean Green Building Certification(KGBC) system to induce the diffusion of sustainable buildings was introduced in 2002 and developed as an improved version of the G-SEED(Green Standard for Energy and Environmental Design) system in 2013 after major revisions. This research examines the importance of assessment criteria on apartment buildings to certify green buildings using the AHP(Analytic Hierarchy Process) method and suggests a new direction on certification assessment standards from the AHP result. In order to apply the AHP method, the survey via e-mail was conducted to design staffs in domestic architectural firms. As a result, assessment criteria such as ecological environment, indoor environment, and energy & environment pollution among 7 main ones proved to be important on assessing the G-SEED system for apartment buildings, while criteria such as land use & transportation, material & resource, water circulation management, maintenance management did relatively unimportant.