• Progress in Superconductivity
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• v.11 no.1
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• pp.47-51
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• 2009

For many large-scale applications of high-temperature superconducting materials, large critical current density ($J_c$) in high applied magnetic fields are required. A number of methods have been reported to introduce artificial pinning centers in $YBa_2Cu_3O_{7-{\delta}}$ films for enhancement of their $J_c$. We studied the microstructures and characteristic of $YBa_2Cu_3O_{7-{\delta}}$ films fabricated on $SrTiO_3$ (100) substrates with ZnO nanorods as pinning centers. Au catalyst nanoparticles were synthesized on STO substrates with self assembled monolayer to control the number of ZnO nanorods. The density of Au nanoparticles is approximately $240{\sim}260{\mu}m^{-2}$ with diameters of $41{\sim}49nm$. ZnO nanorods were grown on STO by hot-walled PLD with Au nanoparticles. Typical size of ZnO nanorod was around 179 nm in diameter and $2{\sim}6{\mu}m$ in length respectively. YBCO films deposited directly on STO substrates show the c-axis orientation, while YBCO films with ZnO nanorods exhibit any mixed phases without any typical crystal orientation.

• Informatization Policy
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• v.23 no.4
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• pp.24-37
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• 2016

An Intelligent information society means intelligent superconducting society that goes beyond information society where information is centered. Now that artificial intelligence is specifically discussed, it is time to start discussing the laws and systems for intelligent information society, where artificial intelligence plays a key role. At some point it may be too late to cope with singularity. Of course, it is not easy to predict how artificial intelligence will change our society. However, there are concerns on what kind of relationship should humans build with AI in the intelligent information society where algorithms rule the world or at least support decision making of humans. What is obvious is that humans dominating AI or ruling out AI will not be the answer. Discussions for legal framework to respond to the AI-based intelligent information society needs to be achieved to a level that replaces the current human-based legal framework with AI. This is because legal improvement caused by the paradigm shift to the intelligent information society may assume emergence of new players-AI, robots, and objects-and even their subjectivation.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.7
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• pp.528-539
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• 2017

Since IoT is expected to enable hyper-connected society to be realized with the advent of the $4^{th}$ Industrial Revolution, many advanced foreign countries as well as United Kingdom identified IoT spectrum policy as one of the first priority in spectrum management in order to cope with the frequency demands required for the promotion of IoT service. In Korea, the frequencies of 110 MHz bandwidth has been also supplied additionaly for IoT in July 2016 in order to activate a promising new IoT industry based on wireless communication, which has great potential for future industrial growth. Therefore, in this paper, we propose spectrum policy and the research and innovation trends on IoT to promote IoT industry by analyzing the major communication network, the key challenge technologies and the spectrum policy framework of foreign countries.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.3
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• pp.457-463
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• 2016

The newly developed super ductile duplex stainless steel (SDSS) has good strength and ductility, and it can be used to reduce weight and improve the fabrication efficiency of a carbody of a rolling stock. In this study, spot weldability tests were conducted to take advantage of SDDSS in a carbody for an intermodal tram. Specimens of various thickness (0.4 to 5.0 mm) were prepared to find the proper welding conditions, and tensile load tests were conducted to evaluate the tensile-shear strength of spot welded joints. Then, nugget diameters were measured to verify the quality. The tensile-shear strength was found to be proportional to the heat parameter. It was verified that the tensile-shear strengths and nugget sizes of the joints satisfy the standard requirements. The overall weldability tests confirmed that SDDSS can be used effectively for the carbody of an intermodal tram.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.17 no.1
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• pp.9-15
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• 2005

Dredged soil from sea has much higher water content than liquid limit of clay and even if small loads apply, it will suffer a great settlement. Therefore it is very difficult to perform a consolidation test with general consolidation apparatus because of high water content. In this study Rowe cell apparatus consolidation tests have been performed with 5 slurry clays of a water content of 100%, 110%, 120%, 133%, and 150%. From the test results the consolidation characteristics such as compression index, secondary compression index, consolidation coefficient, and strain have been investigated with a variation of water content of dredged soil. The equations to get consolidation constants such as a compression index, a coefficient of consolidation, and strain have been proposed with the field water content.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.11
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• pp.2015-2021
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• 2017

Recently, a lot of attention is fallen to IoT(Internet of Things) for hyper-connected society and the number of unlicensed wireless device has been increasing. Thus, this paper analyzed the impact of unlicensed wireless device on the basis of 802.11ah on licensed LTE user equipment in 900 MHz frequency band for efficient frequency use. As the interference analysis method, Minimum Coupling Loss (MCL) method and Monte Carlo (MC) method were used. In case of one interferer, minimum separation distance between interferer and victim was calculated as about 22 m through the MCL method under the assumption of the worst case. The maximum number of interferer to meet the interference probability of 5% below within a cell radius of the victim was computed as about 3000 by using MC method based on statistical technique. The analysis method and results in this paper are expected to be used for the coexistence between unlicensed wireless device and licensed wireless device.

• The Journal of Society for e-Business Studies
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• v.18 no.4
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• pp.25-43
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• 2013

Two of the most important changes in the global market can be represented with Hyper-connection and Glocalization. To cope with these changes and secure the competitive advantages, it is essential to develop the standard organization, policy, processes and criteria for service management. In addition, the service management system is required to effectively support the R&D project management. In this research, an adaptive framework and system architecture for designing R&D project management process using cloud computing has been introduced. With the proposed system, it is able to overcome the limitations of traditional service management and treat the demand from the market in agility. Moreover, it may be possible to present more value than customers want and secure the competitive advantages in the global market with the proposed system.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.3
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• pp.65-72
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• 2020

The Internet of Things(IoT) is to build a hyper-connected society through interconnection, and on this basis, to improve the quality of life and productivity, including solving social problems, and to become the next growth engine for the nation. The open common eco-system pursued by the IoT can start with the under- standing of the word 'open'. The IoT can achieve the expected effect of lowering the barriers to entry of technology development, and in these changes, OSSW and OSHW play a very important role in accelerating IoT eco-system maturity and breaking the boundaries between industries to promote convergence. Recently, it has developed into an intelligent IoT that combines artificial intelligence (AI) with the connectivity of the IoT. Here, I will analyze the direction of development of the IoT through understanding and analysis of open source.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.495-508
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• 2010

Vertical drains are commonly used to accelerate the consolidation process of soft soils, such as dredged materials. The installation of vertical drain provides a radial drainage path to water in the deposit soil in addition to the vertical direction. An estimation of time rate of settlement is considerably complicated when vertical drains are installed to enhance consolidation process of dredged material because the vertical drains are commonly installed before self-weight consolidation is ceased. In this paper, the vertical drain theory developed by Barron(1948) is applied to analyze the non-linear consolidation behavior considering radial drainage. The overall average degree of self-weight consolidation of the dredged soil under the condition that the water is drained in both radial and vertical directions is estimated using the Carillo(1942) formula. In addition, the Morris(2002) theory and the one-dimensional non-linear finite strain numerical model, PSDDF, are applied to analyze the self-weight consolidation in case of only the vertical drainage is considered. The new analysis approach proposed herein can simulate properly the time rate of the self-weight consolidation of dredged materials that is facilitated with vertical drains.

• Journal of the Korean Geotechnical Society
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• v.27 no.5
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• pp.5-15
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• 2011

Recent increase of large scale construction near costal area has also increased the application of soft ground treatment. As a result, solidification with cement and lime which increases stability and durability of soils, is frequently used for surface layer stabilization in soft ground site. While stabilization of very soft clay with high plasticity and compressibility has widely been studied, studies on silty clay with low plasticity and compressibility are relatively rare. In this study, after stabilizing low plasticity silty clay of Songdo area with cement and lime under various water contents, mixing ratio, and curing time, uniaxial compression test and plate load test were performed. Strength properties from both tests were considerably consistent. And trackability of construction equipment on the treated surface layer of dredged land was estimated. Finally, optimum mixing condition for Songdo silty clay was proposed.