• Korean Journal of Computational Design and Engineering
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• v.21 no.2
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• pp.151-158
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• 2016

It is important to analyze dimensional errors occurring during shipbuilding process. A ship is constructed by assembling blocks and installing outfits in assembled ship structure. Blocks and outfits have a main direction that has greater importance than other directions from the view point of dimensional error. Therefore, a main direction should have a greater weighting factor than other directions in order to achieve meaningful inspection results. In this paper, a modified point registration method based on iterative closest point (ICP) is proposed. In this method, a user determines one or two main directions among x, y, and z directions, and then each main direction is made to have a greater weighting factor than other directions. For points registration, mapping between measured points and design points are performed by the modified ICP in which weighting factor assigned to each main direction is considered.

• Communications for Statistical Applications and Methods
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• v.20 no.6
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• pp.455-466
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• 2013

In nested case-control studies, the most common way to make inference under a proportional hazards model is the conditional logistic approach of Thomas (1977). Inclusion probability methods are more efficient than the conditional logistic approach of Thomas; however, the epidemiology research community has not accepted the methods as a replacement of the Thomas' method. This paper promotes the inverse probability weighting method originally proposed by Samuelsen (1997) in combination with an approximate jackknife standard error that can be easily computed using existing software. Simulation studies demonstrate that this approach yields valid type 1 errors and greater powers than the conditional logistic approach in nested case-control designs across various sample sizes and magnitudes of the hazard ratios. A generalization of the method is also made to incorporate additional matching and the stratified Cox model. The proposed method is illustrated with data from a cohort of children with Wilm's tumor to study the association between histological signatures and relapses.

• Survey Research
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• v.2 no.1
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• pp.73-86
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• 2001

In this paper. we conducted an empirical study to investigate the design and weighting effects on descriptive and analytic statistics. We compared the regression models using the design-based approach and the generalized estimating equations (GEEs) approach with the model-based approach through the design and weighting effects analysis.

• Journal of the Chungcheong Mathematical Society
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• v.27 no.3
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• pp.513-521
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• 2014

Via extension of the classical double-Newton method, we propose high-order family of two-point methods in this paper. Theoretical and computational properties of the proposed methods are fully investigated along with a main theorem describing methodology and convergence analysis. Typical numerical examples are thoroughly treated to verify the underlying theory.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.5B
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• pp.529-537
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• 2006

This paper investigates the impacts of the drag-related weighting coefficients on mean velocity and turbulence structures. The transport equations for the Reynolds stress of vegetated open-channel flows are derived by using the temporal- and horizontal-averaging scheme. It is found that the total Reynolds stress of vegetated open channel flows consists of the Reynolds stress due to temporally fluctuating velocities and the Reynolds stress due to spatially fluctuating velocities. The drag-related weighting coefficient $C_{fk}$ for the total Reynolds stress component is found to be unit, while the coefficient for the Reynolds stress due to temporally fluctuating velocities can be negligible. This is the reason why very small weighting coefficients in previous studies yield very good agreements with measured data. In other words, the Reynolds stress due to spatially fluctuating velocities remains still unknown, especially due to the large number of measuring locations. Through a developed Reynolds stress model, vegetated open-channel flows are simulated and compared with measured data from the literature. Comparisons reveal that the computed mean flow and Reynolds stress structures are hardly affected by the drag-related weighting coefficients. However, the computed turbulence intensity profiles are significant different with the drag-related weighting coefficients. A budget analysis of the transport equations for the Reynolds stress component is carried to investigate why turbulence intensity is affected by the drag-related weighting coefficients.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.4D
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• pp.695-702
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• 2006

In GIS-based Spatial Decision-making Support System (SDSS), the Boolean logic by conventional simple overlay method contains two problems. One is losing lots of information in analysis process, the other is unable to reflect of weighting values between evaluated items. Therefore, evaluation system as Analytic Hierarchy Process (AHP) needs to improve these problems effectively. The purpose of this study is to provide the benefit of AHP method and GIS spatial analysis in site analysis for crop cultivation. First, the weighting value of AHP for topography, distribution grade of water, property of soil and slope items are evaluated throughout survey to experts of soil, crop and agricultural management fields. On the basis of these weighting value of AHP by items, site suitability analysis for black raspberry cultivation is performed. To estimate the benefit of AHP method, the current cultivating map of black raspberry is constructed in Ssangchi-myeon district. In comparison with site analysis of Boolean logic, site analysis of AHP method shows more realistic.

• Nuclear Engineering and Technology
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• v.51 no.1
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• pp.163-169
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• 2019

The robust controller synthesis and analysis of the water level process in the U-tube system generator (UTSG) is addressed in this paper. The parameter uncertainties of the steam generator (SG) are modeled as multiplicative perturbations which are normalized by designing suitable weighting functions. The relative errors of the nominal SG model with respect to the other operating power level models are employed to specify the weighting functions for normalizing the plant uncertainties. Then, a robust controller is designed based on ${\mu}$-synthesis and D-K iteration, and its stability robustness is verified over the whole range of power operations. A gain-scheduled controller with $H_{\infty}$-synthesis is also designed to compare its robustness with the proposed controller. The stability analysis is accomplished and compared with the previous QFT design. The ${\mu}$-analysis of the system shows that the proposed controller has a favorable stability robustness for the whole range of operating power conditions. The proposed controller response is simulated against the power level deviation in start-up and shutdown stages and compared with the other concerning controllers.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.42 no.3
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• pp.217-231
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• 2019

The purpose of this study is to analyze the factors influencing consumers' selection of web-toon service through AHP (Analytic Hierarchy Process) analysis and to provide the strategy of web-toon service. To accomplish this study, theories, existing research and references related to AHP were sufficiently examined and selected the factors in the selection criteria. Surveys from consumers who used the web-toon service were conducted with selected factors. Through this, the results were analyzed by AHP analysis to find out the weighting values and the differences were examined and analyzed. The highest weighting factor in the first layer that consists of web-toon service was cinematic quality. The cinematic quality was the most important factor in the selection criteria of customers who use the web-toon service regardless of their preferred genre. Furthermore, it was confirmed that the weighting value or ranking changed in the second layer by genre. In this study, the effective basis of strategy were suggested by ranking the quantitative selection factors according to the preferred genre of consumers using web-toon services. In addition, This research provides some practical implications. That is, the web-toon service provider can easily recognize and respond to the customer's requirements, which factors are important when the customer selects a specific genre from the web-toon genre.

• Journal of Korean Society of Rural Planning
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• v.16 no.3
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• pp.43-49
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• 2010

This study generalized and systemized the unit-project items of 176 project districts for the rural village comprehensive development projects (RVCDP). This paper surveyed opinions of III answerers (7 specialists, 43 agents of Korea Rural Community corporation, and 61 agents of local government of cities and counties) in order to determine the classification system and their corresponding weighting values of the project items using analytic hierarchy process (AHP) method. From the results extracted by project plans of 176 project districts for 5 years from 2004 to 2008, this study decided a hierarchical system for unit-project items of RVCDP by AHP method, which consisted of three steps: 4 items for 1st step, 13 items for 2nd step, and 52 items for 3rd step. The first step contains 4 items of Strength of Rural-urban Exchange & Regional Capability (RURC), Green-income Infrastructure & Facility (GIF), Culture-health-welfare Facility, and Eco-environment & Landscape facility (ELF). In the survey of weighting values with AHP method, the analysis result for the first step showed that in opinion of specialists, GIF is more important than the others while in opinion of the other agents, RURC is more important. In the second step, Product Facility is more important in the specialists, whereas Strength of Resident Capability is the most important in the other agents. Analyzed unit project items as the third step, all answerers evaluated that the Education and Excursion for Rural Resident Capability has the highest weighting values.

• Journal of Korea Water Resources Association
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• v.42 no.2
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• pp.131-139
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• 2009

The weather accidents by global warming effect are increasing rapidly whole world. Flood forcasting system and hydrological database are operated by almost all the countries in the world. An objective of this study is to research revised methods of missing rainfall data and find more effective revised method for this operating system. 194 rainfall data of the Han river basin is used. Arithmetic average method, coefficient of correlation weighting method and inverse distance weighting method are compared to estimate revised methods. The result from the analysis shows that coefficient of correlation weighting method is best quantitatively among the 3 methods.