• Journal of Digital Convergence
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• v.14 no.7
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• pp.145-154
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• 2016

The purpose of this study was to carry out comparative analysis on the world major liner shipping companies' ship investment strategy using Fuzzy-AHP model. In this study, the ship investment factors were firstly selected by literature review and finally adopted them by in-depth interview with experts who had working experiences over 15 years in the field of shipping business. As suggested in the previous research, the liner shipping companies have been classified into four types such as 'ship investment irrelevant to market trend'(Type1), 'ship investment before market rise'(Type2), 'market decline after participation in excessive orders'(Type3), 'avoidance of ship investment during market rise'(Type4) and the comparative analysis were conducted among four ship investment types. According to the results of analysis, ship investment priority in Type1 was freight rates(0.132), price of used ship(0.121) and fleet(0.103). The priority in Type2 was freight rates(0.134), need for ship owner(0.113) and public funding(0.109). Type3 put its priority in freight rates(0.173), fleet(0.169) and the changes in international circumstances(0.121). Type4 considered freight rates(0.239), fleet(0.232) and oil price(0.150) as its priority.

• Journal of Intelligence and Information Systems
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• v.11 no.1
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• pp.35-51
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• 2005

The wide spread of Internet and rapid development of e-commerce-related technology have brought sweeping changes on the traditional commercial transactions. Accordingly, many efforts to transform these transactions electronically under e-commerce environment have been carried out. As most transactions are usually made through negotiations, the function of automated negotiation is also required in the e-commerce environment. This paper aims to develop the method to generate and evaluate the multi-attribute negotiation proposals for automated negotiation systems. To this end the related articles are reviewed and the method dealing with e-negotiation strategy is suggested. In this method, the seller generates his or her own negotiation proposal and then evaluates the buyer's proposal based on SAW (Simple Additive Weighting Method), one of the MADM (Multi Attribute Decision Making) methods. To verify the suggested method, a case study is conducted in the order-based manufacturing environment.

• International Journal of Automotive Technology
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• v.4 no.4
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• pp.181-191
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• 2003

Since the nonlinearity and uncertainties which inherently exist in vehicle system need to be considered in active suspension control law design, this paper proposes a new control strategy for active vehicle suspension systems by using a combined control scheme, i.e., respectively using a genetic algorithm (GA) based self-tuning PID controller and a fuzzy logic controller in two loops. In the control scheme, the PID controller is used to minimize vehicle body vertical acceleration, the fuzzy logic controller is to minimize pitch acceleration and meanwhile to attenuate vehicle body vertical acceleration further by tuning weighting factors. In order to improve the adaptability to the changes of plant parameters, based on the defined objectives, a genetic algorithm is introduced to tune the parameters of PID controller, the scaling factors, the gain values and the membership functions of fuzzy logic controller on-line. Taking a four degree-of-freedom nonlinear vehicle model as example, the proposed control scheme is applied and the simulations are carried out in different road disturbance input conditions. Simulation results show that the present control scheme is very effective in reducing peak values of vehicle body accelerations, especially within the most sensitive frequency range of human response, and in attenuating the excessive dynamic tire load to enhance road holding performance. The stability and adaptability are also showed even when the system is subject to severe road conditions, such as a pothole, an obstacle or a step input. Compared with conventional passive suspensions and the active vehicle suspension systems by using, e.g., linear fuzzy logic control, the combined PID and fuzzy control without parameters self-tuning, the new proposed control system with GA-based self-learning ability can improve vehicle ride comfort performance significantly and offer better system robustness.

• Atmosphere
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• v.26 no.4
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• pp.697-709
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• 2016

This study estimates and evaluates the extreme value of 30 m-resolution daily maximum and minimum temperatures over South Korea, using inverse distance weighting (IDW), parameter-elevation regression on independent slopes model (PRISM) and generalized extreme value (GEV) method. The three experiments are designed and performed to find the optimal estimation strategy to obtain extreme value. First experiment (EXP1) applies GEV firstly to automated surface observing system (ASOS) to estimate extreme value and then applies IDW to produce high-resolution extreme values. Second experiment (EXP2) is same as EXP1, but using PRISM to make the high-resolution extreme value instead of IDW. Third experiment (EXP3) firstly applies PRISM to ASOS to produce the high-resolution temperature field, and then applies GEV method to make high resolution extreme value data. By comparing these 3 experiments with extreme values obtained from observation data, we find that EXP3 shows the best performance to estimate extreme values of maximum and minimum temperatures, followed by EXP1 and EXP2. It is revealed that EXP1 and EXP2 have a limitation to estimate the extreme value at each grid point correctly because the extreme values of these experiments with 30 m-resolution are calculated from only 60 extreme values obtained from ASOS. On the other hand, the extreme value of EXP3 is similar to observation compared to others, since EXP3 produces 30m-resolution daily temperature through PRISM, and then applies GEV to that result at each grid point. This result indicates that the quality of statistically produced high-resolution extreme values which are estimated from observation data is different depending on the combination and procedure order of statistical methods.

• Journal of Korea Port Economic Association
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• v.34 no.1
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• pp.19-34
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• 2018

This study analyzed specific ports' marketing strategies through interviews and, using fuzzy TOPSIS methodology, derived marketing strategies for the Incheon and Pyeongtaek-Dangjin ports by comparing them with the Busan port. Previous studies had concentrated on the Busan port, and the majority of these studies analyzed the present conditions and suggested 4P strategies using a marketing mix. After weighting all of the respondents' answers, the results show that among all marketing strategies, incentive provisions ranked the highest, followed by the intermediary role between the relevant agencies and companies, and last- the agent system for establishing local networks. The fuzzy TOPSIS analysis results showed that the Busan port had the best marketing performance. The most sensitive strategies, based on the sensitivity analysis, were the intermediary role between relevant agencies and companies in the Incheon port, and the incentive provision in Pyeongtaek-Dangjin port. The implications of this study are that the port management agencies' actual marketing strategies were similar to the marketing promotion strategies suggested by previous research, and thus, each port's marketing targets and their characteristics should be clearly defined.

• The Journal of the Korea Contents Association
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• v.11 no.10
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• pp.457-466
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• 2011

In general, drivers need a self-interest information to decide their routes. So, non-governmental sectors, such as Internet Portal Company, make and provide user-oriented contents for drivers in a hurry. But, VMS which is the typical public media always provides traffic-information for drivers without weighting personal characteristics and considering transportation conditions. So in this research, we searched importance and preference of traffic-information contents as IPA(Importance-Performance Analysis)result. We can draw the conclusion that the improvement of traffic-information contents focused on users(drivers) is needed. Specially, we proposed the strategy of VMS according to traffic conditions.

• Journal of Korean Society of Rural Planning
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• v.25 no.1
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• pp.75-87
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• 2019

As the impacts of climate change have been emerged all the way through society, the potential risks specifically on agricultural water and facilities are recently getting concerned. Evaluating vulnerability of agriculture to climate change on is a time-tested strategy. While a number of researches on the adaption and mitigation of climate change were performed in various aspects for sustainable agricultural production, the vulnerability of management system for agricultural water and infrastructure has not been investigated yet. This study is aimed to clarify the definition of vulnerability to climate change, find the major indicators able to presume the vulnerability, and finally determine the relative importance of the indicators based on the specialist questionnaire survey and its analyses. The lists of indicators for major parts of agricultural water management such as, water use, flood control, reservoir related issues, and pumping and drainage systems are initialized referring to the related precedent studies. The primary survey was conducted in the form of Delphi to complement the list and methods and the main survey was then conducted using AHP(Analytic Hierarchy Process) technique to quantitatively prioritize the indicators. The results derived in this study would be directly adopted in weighting importance of indicators to investigate the indicator-based vulnerability analysis to climate change in agricultural water and infrastructure management.

• Journal of the Korea Convergence Society
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• v.10 no.1
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• pp.187-195
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• 2019

There is a growing emphasis on objective and quantified performance measurement methodologies for the interactions that occur within modern companies. This is due to the importance of establishing and practicing future-oriented strategies by estimating the present value of the company and the current energy status through objective evaluation of the company. Therefore, the selection of KPI as a performance index using BSC (Balance Scorecard), which is a recent objective performance measurement methodology, has become very important. Although many studies on existing KPIs have been made in various industries, KPI studies on SI companies have been insufficient. This study focuses on finding KPIs applicable to SI companies. The study on the KPI design system according to general strategy of SI companies and the development of methodology and evaluation index according to index development for each group were carried out and the weighting methodology according to each evaluation index was presented.

• Journal of Preventive Medicine and Public Health
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• v.55 no.1
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• pp.10-18
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• 2022

Disability-adjusted life-year (DALY) estimates may vary according to factors such as the standard life expectancy, age weighting, time preference and discount rate, calculation of disability weights, and selection of the estimation method. DALY estimation methods are divided into the following 3 approaches: the incidence-based approach, the pure prevalence-based approach, and the hybrid approach. These 3 DALY estimation approaches each reflect different perspectives on the burden of disease using unique characteristics, based on which the selection of a suitable approach may vary by the purpose of the study. The Global Burden of Disease studies, which previously estimated DALYs using the incidence-based approach, switched to using the hybrid approach in 2010, while the National Burden of Disease studies in Korea still mainly apply the incidence-based approach. In order to increase comparability with other international burden of disease studies, more DALY studies using the prevalence-based approach need to be conducted in Korea. However, with the limitations of the hybrid approach in mind, it is necessary to conduct more research using a disease classification system suitable for Korea. Furthermore, more detailed and valid data sources should be established before conducting studies using a broader variety of DALY estimation approaches. This review study will help researchers on burden of disease use an appropriate DALY estimation approach and will contribute to enhancing researchers' ability to critically interpret burden of disease studies.

• Journal of the Korean Society for information Management
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• v.40 no.2
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• pp.243-262
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• 2023

In the rapidly developing information technology environment, information management organizations need to effectively evaluate their digital maturity and clarify the direction of improvement to effectively respond to rapidly changing environments. This study derived weights for the digital curation maturity model developed by KISTI from the perspective of digital transformation to facilitate effective evaluation and direction setting of information management organizations. Relative importance was derived as a weight in the major and middle categories of the model through the AHP technique. Summarizing the results, when the major categories of the entire model are measured on the basis of 100 points, technology is 27 points, data is 24 points, strategy is 19 points, organization (manpower) is 16 points, and (social) influence is calculated as 14 points. In addition, weights for each subcategory were presented for each major classification based on a perfect score of 100 points. It is expected that a more objective and reasonable evaluation will be possible by applying the weights for each area derived from this study to the digital transformation maturity evaluation model.