• International Journal of Naval Architecture and Ocean Engineering
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• v.10 no.3
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• pp.307-317
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• 2018

In this study, numerical investigations of the tip clearance flow characteristics of a pumpjet propulsor based on Computational Fluid Dynamics (CFD) method have been presented. The Zwart-Gerber-Belamri (Z-G-B) cavitation model based on Reynolds Averaged Navier-Stokes (RANS) method is employed. The structured gird is applied. The formation and development of the tip clearance flows has been investigated and presented. The structure of the tip leakage vortex has been shown. The radial distributions of different velocity components with different Span along the axial direction have been carried out to present the influence of the tip clearance flow on the main flow. In addition, the influences of the tip clearance size on the pumpjet propulsor performance, including the impact on the velocity flow fields and the cavitation characteristic, have been presented.

• Journal of Surface Science and Engineering
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• v.50 no.3
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• pp.225-229
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• 2017

ZnO nanotubes were synthesized to investigate the effect of wall thickness on the ethanol gas sensing performance. The wall thickness of the nanotubes was varied from approximately 20 to 60 nm. Transmission electron microscopy, X-ray diffraction and SAED (Selected Area Electron Beam Diffraction) analyses showed that the synthesized nanotubes were polycrystalline structured ZnO with the diameter of approximately 200-300nm. The ZnO nanotubes sensor with an optimum wall thickness of 51.8nm showed approximately 8 times higher response, compared to that with 21.14nm wall thick nanotubes, to the ethanol concentration of 500 ppm at the temperature of $300^{\circ}C$. The wall thickness of 51.8nm was found to be a little larger than 46nm, which was theoretically derived Debye length. Along with the study of the wall thickness effect on the performance of the sensors, the mechanisms of gas sensing of the polycrystalline ZnO nanotubes are also discussed.

• Knowledge Management Research
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• v.12 no.4
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• pp.77-90
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• 2011

This study examined the effects of knowledge management strategy and structural capital on organizational performance. Structured capital was classified into three dimensions: organizational culture, knowledge process, and information technology. Data were collected from 251 employees in a public institution. Results indicated that organizational knowledge-based strategy was positively related to employees' job satisfaction, and that information technology-based strategy was positively related to customers' satisfaction and institutional image. Results also indicated that organizational culture and knowledge process were positively related to customers' satisfaction, employees' job satisfaction, and institutional image, whereas informational technology was negatively related to customers' satisfaction and institutional image. Finally, the theoretical and practical implications of the results were discussed.

• International Journal of Knowledge Content Development & Technology
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• v.7 no.4
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• pp.71-84
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• 2017

The paper discusses the nature of Knowledge Organization Systems (KOSs) and shows how these can support digital library users. It demonstrates processes related to integration of KOS like the Dewey Decimal Classification, $22^{nd}$ edition (DDC22) in DSpace software (http://www.dspace.org/) for organizing and retrieving (browsing and searching) scholarly objects. An attempt has been made to use the DDC22 available in Bengali language and highlights the required mechanisms for system-level integration. It may help a repository administrator to build an IDR (Institutional Digital Repository) integrated with SKOS-enabled multilingual subject access systems for supporting subject descriptors based indexing (DC.Subject metadata element), structured navigation (browsing) and efficient searching.

• Applied Microscopy
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• v.45 no.4
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• pp.214-217
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• 2015

This study introduces metal coating as an effective sample preparation method to remove charge-up caused by the shadow effect during field emission scanning electron microscope (FE-SEM) analysis of dynamic structured samples. During a FE-SEM analysis, charge-up occurs when the primary electrons (input electrons) that scan the specimens are not equal to the output electrons (secondary electrons, backscattered electrons, auger electrons, etc.) generated from the specimens. To remove charge-up, a metal layer of Pt, Au or Pd is applied on the surface of the sample. However, in some cases, charge-up still occurs due to the shadow effect. This study developed a coating method that effectively removes charge-up. By creating a converted sample stage capable of simultaneous tilt and rotation, the shadow effect was successfully removed, and image data without charge-up were obtained.

• Journal of Fisheries and Marine Sciences Education
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• v.27 no.6
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• pp.1676-1684
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• 2015

The study was conducted to develop the Practical STEAM education Model. To achieve the goal, we did analysis advanced research, comprehensive review of literature, consultation with research team. As a result, the Practical STEAM education Model is consisted as follow; integrated subjects, object, value and aim, curriculum(method, assessment). The result has defined the concept and theoretical framework of STEAM education curriculum as application aspects, it would help to develop the program with STEAM education curriculum. Later in this study is to develop programs and organize. and It intends to become the base to be able to interest and interest in science education by structured around the status of problems that can be found in the life of around themes STEAM.

• Journal of Korea Society of Digital Industry and Information Management
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• v.12 no.3
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• pp.1-9
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• 2016

The current meaning of "Big Data" refers to all the techniques for value eduction and actionable analytics as well management tools. Particularly, with the advances of wireless sensor networks, they yield diverse patterns of digital records. The records are mostly semi-structured and unstructured data which are usually beyond of capabilities of the management tools. Such data are rapidly growing due to their complex data structures. The complex type effectively supports data exchangeability and heterogeneity and that is the main reason their volumes are getting bigger in the sensor networks. However, there are many errors and problems in applications because the managing solutions for the complex data model are rarely presented in current big data environments. To solve such problems and show our differentiation, we aim to provide the solution of actionable analytics and semantic reusability in the sensor web based streaming big data with new data structure, and to empower the competitiveness.

• Proceedings of the KIPE Conference
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• 2016.07a
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• pp.513-514
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• 2016

본 논문에서는 스위칭 셀 구조의 직접형 PWM ac-ac 컨버터를 이용한 새로운 단상 무효전력 보상 장치를 제안한다. 제안한 보상기는 최근에 개발된 가변 임피던스 개념을 이용한 무효전력 보상기에서 발전된 형태이다. 기존 보상기에는 시스템 신뢰성에 심각한 악영향을 주는 커뮤테이션 문제가 존재하는데 제안한 보상기에서는 스위칭셀 구조와 결합인덕터로 구성된 ac-ac 컨버터를 사용하여서 커뮤테이션 문제를 해결하였다. 이로인해 기존 시스템에 비해 스위칭 신호 구현이 매우 간편하고 RC 스너버가 필요하지 않으며 결과적으로 매우 신뢰성이 높은 시스템을 구현할 수 있다. 간략화 된 단상시스템을 구축하여 실험을 통해 성능을 검증하였다.

• Proceedings of the Korea Contents Association Conference
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• 2006.11a
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• pp.815-818
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• 2006

Lately, the development of the Internet yield to increase the number of game players. The advertisement intended for increasing game players is made an issue of. In this paper, we explain the various cases by using games as the advertising media and analyze their problems. In addition, we propose the structured module to solve the problems and to service efficiently the advertisements.

• Journal of the Korean Home Economics Association
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• v.35 no.4
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• pp.269-282
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• 1997

The purpose of this research is to analyze perceptions of consumers and willingness to play for high-priced food. The price dispersions of four food categories - soybean sprouts, tofu, milk, and egg - were analyzed through the market analysis, and the survey with the structured questionnaire was utilized to get information on the reason why consumers buy and don't buy the high-priced food. It tested whether a consumer would change the choice if the new product information on safety issues is offered and if the price of high-priced food is lowed. Results showed that generally consumers don't have the confidence on the level of safety and comparative advantages of quality of high-priced food, but they just purchase the high-priced food as long as they can afford it.