• Journal of Information Technology Application
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• v.1
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• pp.99-127
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• 1999

Under the concept of global economy, the enterprises are assigning design and production environments around the world in different areas. A serious problem of information exchange emerges as companies use traditional hardware and very distinct softwares appropriate to their field of expertise. To overcome the decreased productivity due to the interruption of information, the concept of simultaneous engineering and concurrent design becomes very significant. In this article, an agent-based ship design system is developed in order to support a cooperation in distributed ship design environments. Above all, the conflicts that occur in the middle of knowledge sharing in the system must be resolved. An approach to do this is the case-based conflict resolution strategy formulated to resolve current conflict on the basis of previous resolved similar cases in agent-based collaborative design system environments. To do this conflict cases that occur in initial ship design stage are extracted. On the basis of the extracted cases, case-base is constructed. In addition conflict resolution handler located in the facilitator is developed to treat conflict problems effectively by reasoning of the case-base and thus presenting an appropriate solution. The validation of developed case-based conflict resolution strategy is evaluated by applying to collaborative design process in initial ship design stage, especially the machinery outfitting design, the preliminary design, the hullform design, and the structural design. Through the help of the cooperation of the design agents, the facilitator, the conflict resolution handler, and the case-based system, a designer can be supported effectively in his/her decision-making based on the previous cases resolved similarly.

• Journal of Intelligence and Information Systems
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• v.13 no.2
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• pp.1-14
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• 2007

Case-based reasoning (CBR) is one of the most widely applied data mining techniques and has proven its effectiveness in various domains. Since CBR is basically based on k-Nearest Neighbors (NN) method, the value of k affects the performance of CBR model directly. Once the value of k is set, it is fixed for the lifetime of the CBR model. However, if the value is set greater or smaller than the optimal value, the performance of CBR model will be deteriorated. In this research, we propose a new method of composing the NN set using similarity scores as themselves, which we shall call s-NN method, rather than using the fixed value of k. In the s-NN method, the different number of nearest neighbors can be selected for each new case. Performance evaluation using the data from UCI Machine Learning Repository shows that the CBR model adopting the s-NN method outperforms the CBR model adopting the traditional k-NN method.

• Journal of the Korean Operations Research and Management Science Society
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• v.23 no.1
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• pp.109-141
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• 1998

Many processes in the industrial realm exhibit sstochastic and nonlinear behavior. Consequently, an intelligent system must be able to nonlinear production processes as well as probabilistic phenomena. In order for a knowledge based system to control a manufacturing processes as well as probabilistic phenomena. In order for a knowledge based system to control manufacturing process, an important capability is that of prediction : forecasting the future trajectory of a process as well as the consequences of the control action. This paper examines the robustness of data mining tools under varying levels of noise while predicting nonlinear processes, includinb chaotic behavior. The evaluated models include the perceptron neural network using backpropagation (BPN), the recurrent neural network (RNN) and case based reasoning (CBR). The concepts are crystallized through a case study in predicting a chaotic process in the presence of various patterns of noise.

• Journal of Intelligence and Information Systems
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• v.11 no.1
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• pp.107-121
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• 2005

Recently, many researches on recommendation systems and collaborative filtering have been proceeding in both research and practice. However, although product items may have multi-valued attributes, previous studies did not reflect the multi-valued attributes. To overcome this limitation, this paper proposes new methodology for recommendation system. The proposed methodology uses multi-valued attributes based on clustering technique for items and applies the collaborative filtering to provide accurate recommendations. In the proposed methodology, both user clustering-based CBR and item attribute clustering-based CBR technique have been applied to the collaborative filtering to consider correlation of item to item as well as correlation of user to user. By using multi-valued attribute-based clustering technique for items, characteristics of items are identified clearly. Extensive experiments have been performed with MovieLens data to validate the proposed methodology. The results of the experiment show that the proposed methodology outperforms the benchmarked methodologies: Case Based Reasoning Collaborative Filtering (CBR_CF) and User Clustering Case Based Reasoning Collaborative Filtering (UC_CBR_CF).

• Education of Primary School Mathematics
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• v.21 no.1
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• pp.55-73
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• 2018

The purpose of this study is to investigate the effects of cognitive activity on cognitive activities that students imagine and cope with continuously changing quantitative changes in functional tasks represented by linguistic expressions, table of value, and geometric patterns, We identified covariational reasoning levels and investigated the characteristics of students' reasoning process according to the levels of covariational reasoning in the elementary quantitative problem situations. Participants were seven 4th grade elementary students using the questionnaires. The selected students were given study materials. We observed the students' activity sheets and conducted in-depth interviews. As a result of the study, the students' covariational reasoning level for two quantities that are continuously covaried was found to be five, and different reasoning process was shown in quantitative problem situations according to students' covariational reasoning levels. In particular, students with low covariational level had difficulty in grasping the two variables and solved the problem mainly by using the table of value, while the students with the level of chunky and smooth continuous covariation were different from those who considered the flow of time variables. Based on the results of the study, we suggested that various problems related with continuous covariation should be provided and the meanings of the tasks should be analyzed by the teachers.

• Journal of Intelligence and Information Systems
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• v.13 no.3
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• pp.141-160
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• 2007

User interface has been regarded as a crucial issue to increase the acceptance of mobile services. In special, even though to what extent the machine as speaker communicates with human as listener in a timely and polite manner is important, fundamental studies to come up with these issues have been very rare. Hence, the purpose of this paper is to propose a methodology of estimating politeness level in a certain context-aware setting and then to design a context-aware system for polite mobile interface. We will focus on Korean language for the polite level estimation simply because the polite interface would highly depend on cultural and linguistic characteristics. Nested Minkowski aggregation model, which amends Minkowski aggregation model, is adopted as a privacy-preserving similarity evaluation for case retrieval under distributed computing environment such as ubiquitous computing environment. To show the feasibility of the methodology proposed in this paper, simulation-based experiment with drama cases has performed to show the performance of the methodology proposed in this paper.

• The KIPS Transactions:PartD
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• v.9D no.6
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• pp.1009-1016
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• 2002

We design and implement a new case-based recommender system using implicit rating information for a digital content site. Our system consists of the User Profile Generation module, the Similarity Evaluation and Recommendation module, and the Personalized Mailing module. In the User Profile Generation Module, we define intra-attribute and inter-attribute weight deriver from own's past interests of a user stored in the access logs to extract individual preferences for a content. A new similarity function is presented in the Similarity Evaluation and Recommendation Module to estimate similarities between new items set and the user profile. The Personalized Mailing Module sends individual recommended mails that are transformed into platform-independent XML document format to users. To verify the efficiency of our system, we have performed experimental comparisons between the proposed model and the collaborative filtering technique by mean absolute error (MAE) and receiver operating characteristic (ROC) values. The results show that the proposed model is more efficient than the traditional collaborative filtering technique.

• Journal of the Korean Institute of Intelligent Systems
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• v.18 no.2
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• pp.175-182
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• 2008

Context-aware service environment should provide many kinds of services according to users' requests. Users want a great variety of services. In response to their demands the service provider should make a new service every time. But making a new service every time may be inefficient even for a small number of users' requests. So, there are studies on how to efficiently support various and complex requests fFom users. In many researches, service compositions have lately attracted considerable attention. However, existing researches have mainly focused on Web services. So they are not proper to rapidly providing services in response to users' requests, especially In context-aware service environment. This paper proposes a rapid service composition using case-based reasoning. For evaluating the proposed algorithm we implement 'purchasing seTvice agent'. With this system, we compare our algorithm and the existing service composition algorithms.

• Journal of Information Technology Applications and Management
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• v.10 no.4
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• pp.119-133
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• 2003

맞춤형 금융상품 설계시스템(Financial Product Factory System)이란 온라인으로 접근하는 고객의 요구사항을 고려하여 고객에게 가장 적합한 금융상품을 실시간으로 설계하여 제공하는 시스템이다. 최근 들어 인터넷 뱅킹 고객의 수가 급증함에 따라 맞춤형 금융상품 설계시스템의 필요성이 대두되고 있으나, 이러한 시스템의 정의나 성격, 필요 기능, 구축 방안에 대한 연구가 되어 있지 않은 실정이다. 본 연구에서는 맞춤형 금융상품 설계시스템의 정의를 내리고, 이 시스템이 갖추어야 할 요구사항을 시스템과 서비스 측면에서 분석한 후, 이 요구사항을 반영하는 시스템의 아키텍처를 제안ㆍ구현한다

• Asian Journal of Innovation and Policy
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• v.4 no.1
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• pp.55-75
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• 2015

The purpose of this study is to find what competence determines the employment of college students using data from the K-CESA (Korea Collegiate Essential Skills Assessment) of a Korean university during 2009-2014. This test comprises of 6 categories of competence: self-management, global readiness, interpersonal relationship, resource/information/technology handling, communication and comprehensive reasoning. In addition to these competences, we add the comprehensive variable, grade point average. In order to identify the qualities of employment, employment was classified into 3 types: all employment, employment in decent jobs and employment in the top 500 companies. Results are as follows: For all employment and decent jobs, GPA and comprehensive reasoning were the meaningful variables. However in case of the top 500 companies, interpersonal relationship was added. Based on the analysis, this study suggests the fundamental concepts of college students' job competence: job specific competence, job basic competence, and basic competence.