• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.12 no.4
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• pp.62-69
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• 1998

The harmonics caused b th nonlinear operation of transmission equipments are not identified yet and have been seldom studied. Sources of harmonics in nonlinear circuit, especially caused by the nonlinear operation of transmission equipments, can be approximately modeled with Duffing's Equation which is often referred in nonlinear mechanical oscillation problem. In this study, a new analytic technique is proposed for the analysis of harmonics n nonlinear circuits using Duffing's Equation and compared with some conventional methods. Finally some case studies were performed to evaluate the performance of proposed method and conventional methods.

• Journal of the Korean Institute of Gas
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• v.20 no.3
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• pp.52-58
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• 2016

In this study, evaluation method for LNG plant FEED is suggested and its validity is confirmed using a well-known decision making technique of Analytic Hierarchy Process (AHP). It is a pairwise comparison technique which can be used when multiple options must be considered for a single decision making problem. In order to develop an objective decision methodology, various decision parameters, sub-parameters as well as the concept of scale of assessment were introduced, and its consistency among these parameters was also checked by calculating the consistency index (C.I.). The methodology suggested in this article will contribute in evaluation of LNG plant FEED with less bias and subjectivity associated with the decision making procedure.

• Journal of the Korean Data and Information Science Society
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• v.24 no.3
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• pp.557-569
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• 2013

Risk management activity for successful defense R&D project should be done anticipatorily and consistently over the entire project period and there should be a priority for management depending on importance of the risk factors. In this study, we verified the reliability and validity through factor analysis for the risk factors selected by the Delphi technique. We also obtained the relative importance of risk factors with analytic hierarchy process (AHP) and decided to prioritize for comparison of domestic and overseas research. According to the study, we found that it is important to settle the requirements and to classify the scope of R&D. It is also considered significant to have reasonable schedule for completion and secure the necessary resources in the early stage of project. Unlike previous studies, it appeared the technical factors are critical elements as well for defense R&D project.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.3
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• pp.917-926
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• 2013

This study presents the feasibility of fuzzy multi-criteria decision making (MCDM) techniques for the robust prioritization of projects. It is applied to water resources planning problem. Results from weighted sum method (WSM), analytic hierarchy process (AHP), revised analytic hierarchy process (R-AHP), and TOPSIS are compared with those from Fuzzy WSM, Fuzzy, AHP, Fuzzy R-AHP, and Fuzzy TOPSIS. For the calculation, all weights on criteria and the normalized data were obtained from the same investigation. As a result, the rankings from four MCDM techniques are slightly different while those from fuzzy MCDM show the comparatively consistent ranking. Therefore, it is desirable to use fuzzy MCDM technique when MCDM is used for the prioritization problem, since fuzzy MCDM can include the uncertain variability of input data and weighting values on criteria.

• Journal of the Korean Institute of Landscape Architecture
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• v.32 no.4
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• pp.94-104
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• 2004

This study creates the LCP (Landscape Control Point) through the survey of spot sites for the quality of landscape assessment, which is based on an objective and departmentalized data base; the landscape assessment was achieved by production of weight value with the AHP (Analytic Hierarchy Process) technique, selection of requisites for the landscape assessment with the IVERSON method and visual area analysis with GIS (Geographic Information System). Futhermore, validity of the landscape assessment was verified by analysis of the correlation between physical amount and aesthetic amount. The purpose of this study is to suggest the basic essential data for landscape assessment and landscape planning by the characteristics of landscape based on verification of the suggested landscape assessment methods. The results of this study are summarized below. 1. In the adaptation of landscape assessment using GIS, the landscape assessment points of LCP 18, 17 and 16, which have more visible elements such as hill area, mountain area, and forest and farm land, were indicated to be higher than the others. In contrast, the landscape assessment points of LCP 13, 6 and 10, which have less visible elements, were relatively lower than the others. 2. In the visible preference measuring method, LCP 4, 14, and 16 showed high points of landscape assessment with 3.46, 3.4, and 3.18 each. With the more natural environments such as hill area, mountain area, and forest and farm land, higher results were shown. In contrast, LCP 7, 1, and 9 showed low points of landscape assessment with 2.24, 2.36, and 2.53 each. 3. In this study, a coefficient of 0.746 was gained by the analysis of correlation between the points of landscape assessment method and the points of visual preference from a slide show. This has 99 percent of probability in statistical data. 4. In conclusion, with the demonstration of the correlation between the landscape assessment method based on the AHP technique and the aesthetic amount (preference proportion), the practical use of landscape assessment can be demonstrated by the suggested landscape assessment method.

• Nuclear Engineering and Technology
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• v.49 no.1
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• pp.148-164
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• 2017

The focus on the issues surrounding spent nuclear fuel and lifetime extension of old nuclear power plants continues to grow nowadays. A transparent decision-making process to identify the best suitable nuclear fuel cycle (NFC) is considered to be the key task in the current situation. Through this study, an attempt is made to develop an equilibrium model for the NFC to calculate the material flows based on 1 TWh of electricity production, and to perform integrated multicriteria decision-making method analyses via the analytic hierarchy process technique for order of preference by similarity to ideal solution, preference ranking organization method for enrichment evaluation, and multiattribute utility theory methods. This comparative study is aimed at screening and ranking the three selected NFC options against five aspects: sustainability, environmental friendliness, economics, proliferation resistance, and technical feasibility. The selected fuel cycle options include pressurized water reactor (PWR) once-through cycle, PWR mixed oxide cycle, or pyroprocessing sodium-cooled fast reactor cycle. A sensitivity analysis was performed to prove the robustness of the results and explore the influence of criteria on the obtained ranking. As a result of the comparative analysis, the pyroprocessing sodium-cooled fast reactor cycle is determined to be the most competitive option among the NFC scenarios.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.16 no.5
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• pp.223-229
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• 2023

This Paper propose the method that measure main system parameters for PI(proportional-integral) current control of a.c. motor adopting the vector control technique. For current control, the PI control input is could be tuning by several selective methods. Among the several methods, the method that using the main system parameters, wire resistance and inductance, are frequently used. In this study, the technique to dissect and measure these two system parameters through the results of simple feedback control. This analytic measurement method is measuring parameters step by step dissecting the results of P control using simple proportional feedback gain about the unit step or multiple step reference command. This strategy is an real time analytic measurement method that calculate current control gains of torque component and flux component both for vector control of A.C. motor without introducing the further measurement circuits and complex measuring algorithms.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.59 no.4
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• pp.354-361
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• 2023

In this study, the AHP (analytic hierarchy process) technique was used to analyze the risk of expected risk factors and fishing possibilities during gillnet fishing within the floating offshore wind farms (floating OWF). For this purpose, the risks that may occur during gillnet fishing within the floating offshore wind farms were defined as collisions, entanglements, and snags. In addition, the risk factors that cause these risks were classified into three upper risk factors and ten sub risk factors, and the three alternatives to gillnet fishing available within the floating OWF were classified and a hierarchy was established. Lastly, a survey was conducted targeting fisheries and marine experts and the response results were analyzed. As a result of the analysis, among the top risk factors, the risk was the greatest when laying fishing gear. The risk of the sub factors for each upper risk was found to be the highest at the berthing (mooring), the final hauling of fishing net, and the laying of the bottom layer net. Based on the alternatives, the average of the integrated risk rankings showed that allowing full navigation/fisheries had the highest risk. As a result of the final ranking analysis of the integrated risk, the overall ranking of allowing navigation/fisheries in areas where bottom layer nets were laid was ranked the first when moving vessels within the floating OWF was analyzed as the lowest integrated risk ranking of the 30th at the ban on navigation/fisheries. Through this, navigation was analyzed to be possible while it was analyzed that the possibility of gillnet fishing within the floating OWF was not high.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.36C no.7
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• pp.1-9
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• 1999

This paper presents an analytic 3rd order calculation methods, without simulations, for delay time of RC-class circuits which are conveniently used to on-chip interconnects. While the proposed method requires comparable evaluation time than the previous 2nd order calculation method, it ensures more accurate results than those of 2nd order method. The proposed analytic delay calculation method guarantees allowable error tolerances when compared to the results obtained from the AWE (Asymptotic Waveform Evaluation) technique and has better performance in evaluation time as well as numerical stability. The first algorithm of the proposed method requires 8 moments for the 3rd order approximation and yields more accurate delay time approximation. The second algorithm requires 6 moments for the 3rd order approximation and results in shorter evaluation time, the accuracy of which may be less than the first algorithm.

• Journal of Intelligence and Information Systems
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• v.17 no.4
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• pp.1-17
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• 2011

In order to maintain customer satisfaction and to remain productive and efficient in today's global competition, mass customization is adopted in many leading companies. Mass customization through product family and product platform enables companies to develop new products with flexibility, efficiency and quick responsiveness. Thus, product family strategy based on product platform is well suited to realize the mass customization. Product family is defined as a group of related products that share common features, components, and subsystems; and satisfy a variety of market niches. The objective is to propose a product family design strategy that provides priority weights among product components by satisfying customer requirements. The decision making process for a new product development requires a multiple criteria decision making technique with feedback. An analytical network process is adopted for the decision making modeling and procedure. For the implementation, a netbook product known as a small PC which is appropriate for the product family model is adopted. According to the proposed architecture, the priority weight of each component for each product family is derived. The relationship between the customer requirement and product component is analyzed and evaluated using QFD model.