• Journal of the Korean Society for Railway
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• v.12 no.3
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• pp.427-436
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• 2009

This paper introduced Railway Network Design Problem (RNDP) to provide priority decisions on high-speed railway investment scenarios defined by various network segments and train systems. The RNDP optimizes the objective functions of minimize total travel time. Results show that the priority of high-speed railway investment is found to be East-west, West-coast, and South-coast line respectively. An entirely new line built with 400km/h is found to be the best alternative to East-west line. Regarding West-coast and South-coast line, the combined alternative of upgrading Geolla and Kyeonjon line with 200km/h and building a new line with 400km/h and 350km/h for remains of each line is the best.

• Journal of KIISE:Software and Applications
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• v.29 no.3
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• pp.156-166
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• 2002

Decision tree induction is a kind of useful machine learning approach for extracting classification rules from a set of feature-based examples. According to the partitioning style of the feature space, decision trees are categorized into univariate decision trees and multivariate decision trees. Due to observation error, uncertainty, subjective judgment, and so on, real-world data are prone to contain some errors in their feature values. For the purpose of making decision trees robust against such errors, there have been various trials to incorporate fuzzy techniques into decision tree construction. Several researches hove been done on incorporating fuzzy techniques into univariate decision trees. However, for multivariate decision trees, few research has been done in the line of such study. This paper proposes a fuzzy decision tree induction method that builds fuzzy multivariate decision trees named fuzzy oblique decision trees, To show the effectiveness of the proposed method, it also presents some experimental results.

• Journal of Information Technology Services
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• v.5 no.2
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• pp.155-168
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• 2006

Software product line is a software product or a set of software system, which has common functions. We can develop a specific software product, which satisfies requirements of a particular market segment and a mission in a specific domain by reusing the core asset such as the developed software architecture through the software product line. Software development methodology based on the software product line can develop a software more easily and fast by reusing the developed software core asset. Developed countries of software technology select software product line as a core field of software production technology, and support technology development. In case of USA, CMU/SEI(Carnegie Mellon University/Software Engineering Institute) developed product-line framework 4.0 together with the industry and the Department of Defense. Europe is supporting the development of product line technology through ITEA(IT for European Advancement) program. However, industries in our country understand the necessity of software production technology based on product line concept for the purpose of increasing productivity, it is not sufficient to invest for this technology development. In this paper, we aim to construct the common architecture of software product line for production of the software product line.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.2
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• pp.315-321
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• 2011

Since the MB-OFDM(Multi-Band Orthogonal Frequency Division Multiplexing) is an ultra wideband communication system operated on ISM(Industrial, Scientific and Medical) band, DAA(Detect-And-Avoid) is required for co-existence with the other communication service. In this paper we propose the new detection algorithm based on decision-feedback, which shows faster convergence time and less complexity than previous works. The proposed algorithm detects interference above -20dB in AWGN(Additive White Gaussian Noise) and LOS(Line-Of-Sight) channel, and close to AWGN in non-LOS channel under appropriate channel clipping.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2006.10a
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• pp.176-183
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• 2006

A novel intelligent anti-collision decision-making supporting system is addressed in this paper. To obtain precise anti-collision information capability, an innovative neurofuzzy network is proposed and applied. A fuzzy set interpretation is incorporated into the network design to handle imprecise information. A neural network architecture is used to train the parameters of the Fuzzy Inference System (FIS). The learning process is based on a hybrid learning algorithm and off-line training data. The training data are obtained by trial manoeuvre. This neurofuzzy network can be considered to be a self-learning system with the ability to learn new information adaptively without forgetting old knowledge. This supporting system can decrease ship operators' burden to deal with bridge data and help them to make a precise anti-collision decision.

• Korean Journal of Childcare and Education
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• v.10 no.1
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• pp.81-94
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• 2014

This study is intended to identify the motivations for seeking child care credentials through online education and factors influencing the career decision-making. The study was conducted among students taking child care courses online, and data was analyzed through t-test, F-test, Scheffe posteriori test, and hierarchical regression analysis. The findings are as follows. 1) Motivation for seeking the credentials varied depending on background variable. Livelihood was a stronger motivation for low-income group than higher come group. Self-realization desire was a stronger motivation for the group with low education level than the group with higher education level. 2) Age affected the participants' career decision-making. The younger they were, the more dependent they were on other people's advice. 3) Different variables influenced the students' rational, intuitional, and dependent career-decision making. Factors influencing their rational career decision-making were age, motivation to acquire the credentials for making a living, and motivation for building a better future. For intuitional career decision-making, age affected the decision. For dependent career decision-making, motivation to seek credentials for making a living was an influencing variable.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.8
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• pp.11-18
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• 1995

This paper proposes a nonlinear adaptive equalizer which is based on fuzzy rules and fuzzy inference of several affine mapping for the received channel data. The proposed nolonlinear adaptive equalizers with the significantly lower computational complexity. Also it can be applied to the on-line adaptation environments owing to its fast convergence characteristics and the lower computational load. When using the decision feedback vectors, this equaalizer can be easily realized in the form of the DFE structure with out the requirement for the perfect channel knowledge as in the case of the fuzzy adaptive filter.

• Korean Management Science Review
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• v.22 no.2
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• pp.35-49
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• 2005

When new services are introduced, interaction among existing and new services has to be considered. The interaction can be characterized by the substitution or complementary effect among services. This paper analyzes how the interaction among services affects the customers' subscription decision in telecommunication services industry. Based on a face-to-face in-depth survey from a sample of 1,200 respondents, a new wireless internet access service or WiBro is analyzed to identify the substitution/complementary effect in relation to the existing other telecommunication services. Additionally, the important factors explaining both customers' subscription and substitution decisions are identified. The analysis results indicate that males and students are more likely to subscribe WIBro service. Interestingly, family size positively affects the subscription decision. However, heavy users of on-line game are reluctant to subscribe WiBro service. Among the potential WiBro subscribers, the customers who are less satisfied with the existing fixed line broadband internet access service are more likely to stop subscribing the fixed line service, which implies substitution by a new service. We believe that the consideration of the interactions among services is essential to devise a winning strategy for the new services in the highly uncertain telecommunications business environment.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.507-510
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• 2016

SNS connect off-line and on-line so that it forms a relationship by sharing users' life and interests. Especially, marketing through SNS is not only economical also it spreads in the fast pace. Thus, many enterprise recognize SNS as a part of platform of ads and they are constantly investing on SNS ads. Also, with the spread of smartphones, the rate of adolescents who use SNS has soared and the rate of exposure to SNS ads also has increased. However, SNS ads have great impact on adolescents'decision-making, because their values of decision-making has not been well developed so that they are easy to influenced by external factors. Therefore, this study aims to understand the effect of SNS ads on adolescents'decision-making.

• KIEAE Journal
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• v.9 no.5
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• pp.13-20
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• 2009

This study suggested practical application of decision aid tool on re-evaluation of current buildings with a focus on a energy and economics evaluation methodology. In Europe, over forty percent of all construction activities are for retrofit. For efficient construction, various tools for re-evaluating existing buildings have been developed and are in use. Legislations of relevant laws and studies are actively initiated. In particular, EPIQR (Energy Performance Indoor environment Quality Retrofit), which was developed through the EU's Third and Fourth Framework Programs laid a foundation on a new concept-based decision aid tool for re-evaluation of existing buildings. As for actual applications, based on this, EPIQR+ was developed to be in line with a building maintenance guideline (SIA 469) and is actively applied to public buildings. This tool quantifies the degree of damages of existing buildings and suggests alternatives to users in energy (SIA 380/1) and economical perspectives. This study examined these preceding tools and suggested some trenchant approaching for more comprehensive and efficient use of re-evaluation tools in building maintenance.