• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.2
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• pp.664-677
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• 2014

Wind energy has proven its viability by the emergence of countless wind turbines around the world which greatly contribute to the increased electrical generating capacity of wind farm operators. These infrastructures are usually deployed in not easily accessible areas; therefore, maintenance routines should be based on a well-guided decision so as to minimize cost. To aid operators prior to the maintenance process, a condition monitoring system should be able to accurately reflect the actual state of the wind turbine and its major components in order to execute specific preventive measures using as little resources as possible. In this paper, we propose a fault detection approach which combines cluster analysis and frequent pattern mining to accurately reflect the deteriorating condition of a wind turbine and to indicate the components that need attention. Using SCADA data, we extracted operational status patterns and developed a rule repository for monitoring wind turbine systems. Results show that the proposed scheme is able to detect the deteriorating condition of a wind turbine as well as to explicitly identify faulty components.

• Journal of Digital Contents Society
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• v.9 no.2
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• pp.251-260
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• 2008

In internet being a repository of massive information, we easily may not find our desired information, this issue also exists in e-commerce which gets rapid growth. In most of e-commerce sites, the methods furnishing information have been made use of statistical analysis or simple process by category-oriented, but these can't represent diverse correlation among products information and also hardly reflect users' purchasing patterns precisely. In this thesis, we propose more efficient web mining ways for discovering interesting information using effective clustering in e-commerce, which get achieved more suitable relationship among products information using both sequential patterns and association rules in category-independent, and experiments show the efficiency of our proposed methods. And we propose search using effective clustering rapidly.

• The Journal of the Korea Contents Association
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• v.10 no.8
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• pp.26-31
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• 2010

This research does focus on realization of customizing recommendation service that all of formal, or informal learning is accomplished at real time according to worker's current situation or business context corresponding with the individual ability and the learning progress at industry or education field. For this, we designed the customizing intelligent recommendation system based on compound knowledge that workers can listen to coaching advices at real time and to retrieve and recommend multidimensional relation easily. Also, we constructed the repository based on compound knowledge and process engine for efficient management of compound knowledge. In specific industry, expert solution or coaching service will be created using the knowledge which is accumulated in long-term.

• Nuclear Engineering and Technology
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• v.42 no.2
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• pp.145-150
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• 2010

The paper is describing work being developed in the frame of a 5-year IAEA Coordinated Research Programme (CRP) started in late 2005. Participants gained knowledge of modelling methodologies and experience in the development and use of rather sophisticated simulation tools in support of site characterization and performance assessment calculations. These goals were achieved by a coordinated effort, in which the advantages and limitations of numerical models are examined and demonstrated through a comparative analysis of simplified, illustrative test cases. This knowledge and experience should help them address these issues in their own country's nuclear waste program. Coordination efforts during the first three years of the project aimed at enabling this transfer of expertise and maximizing the learning experience of the participants as a group. This was accomplished by identifying common interests of the participants (i.e., Process Modelling and Total System Performance Assessment methodology), and by defining complementary tasks that are solved by the members. Synthesis of all available results by comparative assessments is planned in the coming months. The project will be completed end of 2010. This paper is summarizing activities up to November 2009.

• The Journal of Society for e-Business Studies
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• v.14 no.1
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• pp.81-92
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• 2009

In order to use a RDBMS as the repository for product information, it is essential that the ontological query be processed effectively and answered properly, satisfying the user's expectations for an ontological query process. To be well-processed ontological queries, the key point is whether the various semantic relationships among the concepts of the product information are likewise well-processed. For feasibly processing a semantic query, we need to consider how the product ontology data is designed and stored in RDBMS. In this paper, we present how a RDB schema for the product ontology could be designed and queried.

• Journal of Arbitration Studies
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• v.9 no.1
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• pp.367-390
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• 1999

The basic requirements for conducting electronic commerce include confidentiality, integrity, authentication and authorization. Cryptographic algorithms, make possible use of powerful authentication and encryption methods. Cryptographic techniques offer essential types of services for electronic commerce : authentication, non-repudiation. The oldest form of key-based cryptography is called secret-key or symmetric encryption. Public-key systems offer some advantages. The public key pair can be rapidly distributed. We don't have to send a copy of your public key to all the respondents. Fast cryptographic algorithms for generating message digests are known as one-way hash function. In order to use public-key cryptography, we need to generate a public key and a private key. We could use e-mail to send public key to all the correspondents. A better, trusted way of distributing public keys is to use a certification authority. A certification authority will accept our public key, along with some proof of identity, and serve as a repository of digital certificates. The digital certificate acts like an electronic driver's license. The Korea government is trying to set up the Public Key Infrastructure for certificate authorities. Both governments and the international business community must involve archiving keys with trusted third parties within a key management infrastructure. The archived keys would be managed, secured by governments under due process of law and strict accountability. It is important that all the nations continue efforts to develop an escrowed key in frastructure based on voluntary use and international standards and agreements.

• Journal of the Korean Institute of Intelligent Systems
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• v.14 no.7
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• pp.816-820
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• 2004

Clustering is a process of dividing similar data objects in data set into clusters and acquiring meaningful information in the data. The main issues related to clustering are the effective clustering of high dimensional data and optimization. This study proposed a method of measuring similarity based on SVM and a new method of calculating the number of clusters in an efficient way. The high dimensional data are mapped to Feature Space ones using kernel functions and then similarity between neighboring clusters is measured. As for created clusters, the desired number of clusters can be got using the value of similarity measured and the value of Δd. In order to verify the proposed methods, the author used data of six UCI Machine Learning Repositories and obtained the presented number of clusters as well as improved cohesiveness compared to the results of previous researches.

• Journal of the Korea Society of Computer and Information
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• v.8 no.2
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• pp.16-23
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• 2003

In most organizations, the relational DBMS was used for store and manage XML documents due to the pre-established relational DBMS. But, relational DBMS has some problems. They has the possibilities of informational loses in the process of mapping the structure of XML documents to RDB, and they require expensive cost to reflect all XML properties. Thus, this paper was intended to design and implement XML document management system which utilize O2 DBMS-object oriented DBMS in order to overcome the existing problem and reflect all XML Properties. The XML document management system purposed in this thesis has multiple function, such as the library service function for XML documents-check-in/check-out, versioning, user access management-, dynamic indexing and retrieval, and publishing function using style sheet.

• Smart Media Journal
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• v.6 no.3
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• pp.75-82
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• 2017

Recently, the marine monitoring technology is actively being studied since the sea is a rich repository of natural resources that is taken notice in the world. In particular, the marine environment data should be collected continuously in order to understand and analyze the marine environment, however the study of automatic monitoring of marine environment in Korea is not enough. In this paper, we proposed the marine environment monitoring system based on open source. The proposed system can be designed as a scale out system using Hadoop based time series database which it can easily process the increasing collection data by a scale out computer resources. It can also be used to analyze marine data by visualizing collected data.

• Nuclear Engineering and Technology
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• v.49 no.5
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• pp.1010-1018
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• 2017

The European Treatment and Disposal of Irradiated Graphite and other Carbonaceous Waste project sought to develop best practices in the retrieval, treatment, and disposal of irradiated graphite including other irradiated carbonaceous waste such as structural material made of graphite, nongraphitized carbon bricks, and fuel coatings. Emphasis was given on legacy irradiated graphite, as this represents a significant inventory in respective national waste management programs. This paper provides an overview of the characteristics of graphite irradiated during its use, primarily as a moderator material, within nuclear reactors. It describes the potential techniques applicable to the retrieval, treatment, recycling/reuse, and disposal of these graphite wastes. Considering the lifecycle of nuclear graphite, from manufacture to final disposal, a number of waste management options have been developed. These options consider the techniques and technologies required to address each stage of the lifecycle, such as segregation, treatment, recycle, and ultimate disposal in a radioactive waste repository, providing a toolbox to aid operators and regulators to determine the most appropriate management strategy. It is noted that national waste management programs currently have, or are in the process of developing, respective approaches to irradiated graphite management. The output of the Treatment and Disposal of Irradiated Graphite and other Carbonaceous Waste project is intended to aid these considerations, rather than dictate them.