• Nuclear Engineering and Technology
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• v.41 no.8
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• pp.1045-1052
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• 2009

A calculation model is developed to predict the transient free surface flow on the containment floor following a loss-of-coolant accident (LOCA) of pressurized water reactors (PWR) for the use of debris transport evaluation. The model solves the two-dimensional Shallow Water Equation (SWE) using a finite volume method (FVM) with unstructured triangular meshes. The numerical scheme is based on a fully explicit predictor-corrector method to achieve a fast-running capability and numerical accuracy. The Harten-Lax-van Leer (HLL) scheme is used to reserve a shock-capturing capability in determining the convective flux term at the cell interface where the dry-to-wet changing proceeds. An experiment simulating a sudden break of a water reservoir with L-shape open channel is calculated for validation of the present model. It is shown that the present model agrees well with the experiment data, thus it can be justified for the free surface flow with accuracy. From the calculation of flow field over the simplified containment floor of APR1400, the important phenomena of free surface flow including propagations and interactions of waves generated by local water level distribution and reflection with a solid wall are found and the transient flow rates entering the Holdup Volume Tank (HVT) are obtained within a practical computational resource.

• Journal of Welding and Joining
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• v.33 no.3
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• pp.40-46
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• 2015

Welding is one of the most fundamental and necessary work in the industry that demand sophistication of skilled workers. This study is to introduce welding simulator as a training tool, to verify its effectiveness and to measure satisfaction of the trainees. A group of freshman students at a Korea Polytechnics College in their twenties with less experience of welding participated in the study. They were divided into two groups and took a traditional training course (comparison group) and a training course with welding simulator applied reality/haptic technology (experimental group) for same hours respectively. To evaluate training effect, a national certificate test and a survey based on Phillips' ROI (Return on Investment) methodology were conducted by the students and the college respectively. And satisfaction survey among the students based on Kirkpatrick's Four-Level Evaluation Model was also carried out. The results showed that all students in the experimental group passed the national certificate test and the ROI of the experimental group for five years were 110% higher than the comparison group. Furthermore, 25% more students in the experimental group replied "very satisfied" about the overall training course and 75% more students in the same group found that the simulation was very similar to the real welding.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1759-1764
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• 2005

Human Adaptive Mechatronics(HAM) is a new concept which was proposed in our university's research project sponsored by Japanese Ministry of Education, Sports, Culture, Science and Technology(MEXT), and is defined as "intelligent mechanical systems that adapt themselves to the user's skill under various environments, assist to improve the user's skill, and assist the human-machine system to achieve best performance". In this paper, the concept and key-items of HAM are mentioned. And the control strategy to realize a HAM human-machine system is explained in the case of physical-interface system, i.e. haptic system. The proposed assist-control of a force-feedback type haptic system includes online estimation of a operator's control characteristics, and a `force assist' function implemented as a change in the support ratio according to the identified skill level. We developed a HAM-haptic device test system, executed evaluation experiments with this apparatus, and analyzed the measured data. It was confirmed that the operator's skill could be estimated and that operator's performance was enhanced by the assist-control.

• The Journal of Society for e-Business Studies
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• v.2 no.1
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• pp.1-20
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• 1997

This study aims to suggest CALS implementation strategies and policies for information-based management of small and medium companies in Korea. At the turning point from traditional document-based management to recent digital-based one, it is well known that implementation of CALS concept is crucial for advancing business management of small and medium enterprises In order to attack the aim, this paper critically analyzes the empirical difficulties and obstacles of the current information-based management of small and medium companies in Korea. On the basis of the above analysis, this paper suggests the strategic plans and policies of CALS implementation for small and medium enterprises in Korea as follows. First, government should provide the supporting policies and proper system so that the large enterprise can be linked with small and medium companies for sharing necessary information. Second, similar enterprises should be integrated on the basis of information and automation evaluation. Third, implementation strategies and plans should be advanced on the basis of the informationalized phases with respect to the technology level of small and medium enterprises. For more efficient CALS implementation, this paper also proposes the following subsidiary policies. First, it is substantially important to publicize the nation-wide spreading of CALS mind. Second, it is strongly recommended to educate and train CALS specialist on a consistant basis. Third, government should support the enterprises by providing sufficient fund for CALS implementation. Fourth, the ideal CALS implementation models for small and medium enterprises should be developed. Fifth, the consulting and training program for CALS implementation should be established through ECRC (Electronic Commerce Resource Center). My study was based upon the enterprises' responses to the questionaires I made

• Journal of Information Technology Applications and Management
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• v.16 no.4
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• pp.93-107
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• 2009

This study investigated consumer preferences for Internet medical information service in China using the multi-attribute utility theory. The multi-attribute utility theory is a compositional approach for modeling consumer preferences wherein researchers calculate the overall service utility by summing up the evaluation results for each attribute. We found that Chinese Internet medical information users consider the availability of information and quick response to be the most important attributes. Further, they think that the comment feature is less important as compared to other attributes such as costs and updates. In addition, we found that the Internet users having more Internet experience consider these attributes to be more important as compared to the people who are just beginning to surf the Internet. For any successful Internet business, Internet marketers should assess individual-level preference and accordingly organize a fresh campaign. As of now, Internet marketers need estimation methods to predict the market performance of new services in many different business environments. We believe that the multi-attribute utility theory is a useful approach in this regard.

• Journal of Information Technology Applications and Management
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• v.23 no.3
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• pp.71-86
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• 2016

This paper proposes a new software quality model composed of a hierarchy of software quality views and three software quality characteristics models. The software view hierarchy is composed of two levels : end view and means view at the first level, contingency view and intrinsic view as sub-views of means view. Three software quality characteristics models are activity quality characteristics model, contingency quality characteristics model, and intrinsic quality characteristics model, which correspond to end view, contingency view, and intrinsic view respectively. This paper also reclassifies characteristics of ISO/IEC 25000 series SQuaRE's software product quality model according to the proposed software quality model. The results illustrate clearly the shortcomings of SQuaRE's product quality model and how to overcome them. First of all, most of SQuaRE's product characteristics should be redefined and conceptually clarified according to the views on which they are really rested. Much more characteristics should be supplemented too. After that, rigorous empirical researches will become relevant. Causal relationships between activity quality characteristics and characteristics of means view should be empirically researched.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.54 no.2
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• pp.69-75
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• 2005

In order to improve the reliability of high voltage rotating machines and mold transformers, it is necessary to understand the breakdown mechanism and life assessment of the high voltage winding parts. Especially the on-line PD test provides the ability to monitor effects, such as slot discharge, internal discharge, and end-winding discharge without interrupting the electrical machines, this method has been proven the major testing technology. Capacitive couplers have been the most widely used sensors for the on-line partial discharge detection in rotating machines nowadays. This paper deals with the electrical characteristics and long-term reliability of a ceramic coupler(CC), which can be easily mounted into high voltage input terminal part, has been developed and tested to continuously measure PD activity during operating condition. This paper presents electrical characteristics (dielectric loss angle, capacitance, PD inception level, breakdown voltage, and frequency response bandwidth) and long-term life test result of the developed 6.6 kV class on-line ceramic coupling sensor. It was found that this sensor had good electrical characteristics to detect PD activity during the operating condition with its detection frequency band is between several and several tens MHz. Also, the voltage life of the 6.6kV class ceramic coupler was calculated over 60 years.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.7 no.1
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• pp.247-262
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• 1994

This study is concerned with analysis of all the reviews published by the reviewing periodicals, The Book Review Culture and The Korean Publishing Journal, from 1991 to 1993. The result of analysis for 736 reviews are followed： 1) The percentage of reviews in the field of philosophy & religion, literature ＆ language, science ＆ technology is lower than the percent-age of books published. But in the field of history and social science the reviewing is proportionately higher than the publishing. 2) Book reviews are prepared by professors, literary reviewers, researchers, and experts in the particular subject field except librarian. 3) Basic elements of reviewing are the career and view point of author, trends of suject field, content, value, omissions, limitations, and format of book, reader's level, etc. Ideal method of book criticism may be summarized as follows： 1) The criterion of book selection are the book's value, the social . demand, and the proportion of titles published. 2) For the unbiased criticism, it should be written by the experienced librarian rather than the experts of particular subject field. 3) Book criticism need to provide not only guide to new books but also interpretation and evaluation about each book for its reader.

• Ocean and Polar Research
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• v.27 no.1
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• pp.97-108
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• 2005

The International Seabed Authority (ISA) formally came into existence upon the entry into force of the UNCLOS on 16 November 1994. By adopting the Implementing Agreement in 1994, UNCLOS has the universality as a Magna Carta of International Ocean Regime, and the Deep Seabed Mining Regime could be operated as a unique one for the benefit of mankind. During last 10 years, ISA established the institutional framework successfully and made substantial and tangible progress in formulating the rules, regulations and procedures for the prospecting and exploration for polymetally nodules. Furthermore, RPI's obligations had been carried out completely, and the 7 RPI made contract with ISA to become a contractor who has an at least 15 you exclusive right for exploration in their allocated site. However, due to the uncertainty of commercial mining, the number of representatives from developing countries has been getting looser and looser and ISA has a problem of quorum of the Assembly. Land-based producers took a very strong opposite position to the contractors to make their loss in the minimum level. For the next decade, it might be prospected that ISA will focus on monitoring the contractor's activities, making rules, regulations and procedures for exploration on cobalt rich crust, sulphide and methane hydrate and implementing environment studies.

• Asia pacific journal of information systems
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• v.16 no.1
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• pp.1-21
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• 2006

e-Learning can be seen as not only one of Internet-based information technologies which can provide education services but also one of teaching-learning methods which can implement self-directed learning. Thus, for evaluation of e-Learning effectiveness, both information-technology-based learning environment and learners' abilities in self-learning and computer-using should be considered simultaneously. This study suggests a research model for evaluating the effectiveness of e-Learning, which is theoretically based on information systems success model, constructivism and self-efficacy. The model is composed of three parts: effectiveness, learning environment, and learners' self-efficacy. Effectiveness is a part of dependent variables: satisfaction and academic performance. Learning environment and learners' self-efficacy can be considered as two sets of explanation variables for effectiveness. The former consists of learning management system, learning contents, and interactions that are provided bye-Learning and the latter means learners' self-regulated efficacy and computer self-efficacy. We show validity of the model empirically by surveying the college students who have experienced e-Learning. In result, most of all hypotheses suggested in this model are accepted in low significant level.