• Transactions of the Korean hydrogen and new energy society
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• v.22 no.2
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• pp.178-183
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• 2011

Metal hydride alloys are a promising type of material in hydrogen storage applications, allowing for low-pressure, high-density storage. However, while many studies are being performed on enhancing the hydrogen storage properties of such alloys, there has been little research on large-scale storage vessels which make use of the alloys. In particular, large-scale, high-density storage devices must make allowances for the inevitable generation or absorption of heat during use, which may negatively impact functioning properties of the alloys. In this study, we develop a numerical model of the discharge properties of a high-density MH hydrogen storage device. Discharge behavior for a pilot system is observed in terms of temperature and hydrogen flow rates. These results are then used to build a numerical model and verify its calculated predictions. The proposed model may be applied to scaled-up applications of the device, as well as for analyses to enhance future device designs.

• Journal of The Korean Astronomical Society
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• v.27 no.2
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• pp.147-158
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• 1994

We have obtained high angular resolution maps toward a molecular cloud associated with an HII region S287 and studied mainly kinematics of the cloud. The mapped region is 1.5 square degrees of the cloud in the transitions of $^{12}CO\;and\;^{13}CO\;J=1-0$. We have obtained a large range of mass, $1.3\times10^4M_\bigodot$, to $7.2{\times}10^4M_{\bigodot}$ using three different techniques. The S287 molecular cloud shows a very disturbed feature: velocity field of the cloud is very complicated, and shows several arcs. It is likely that the southern part of cloud is being disrupted by the residing HII region S287 as well as external perturbing sources. In addition to an HII region, five bipolar outflows are also disturbing the molecular gas significantly. The large virial mass and the very disturbed morphology may reflect the fact that the cloud is not gravitationally bound system, as in the case of nearby giant molecular cloud (GMC) G216-2.5. The several arc structure and the filamentary features are possibly driven by external strong stellar winds, and these external perturbing sources may be driving the second generation of star-forming activities on the edges of the S287 molecular cloud.

• Clinical and Experimental Reproductive Medicine
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• v.49 no.4
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• pp.225-238
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• 2022

The ultimate goal of human assisted reproductive technology is to achieve a healthy pregnancy and birth, ideally from the selection and transfer of a single competent embryo. Recently, techniques for efficiently evaluating the state and quality of preimplantation embryos using time-lapse imaging systems have been applied. Artificial intelligence programs based on deep learning technology and big data analysis of time-lapse monitoring system during in vitro culture of preimplantation embryos have also been rapidly developed. In addition, several molecular markers of the secretome have been successfully analyzed in spent embryo culture media, which could easily be obtained during in vitro embryo culture. It is also possible to analyze small amounts of cell-free nucleic acids, mitochondrial nucleic acids, miRNA, and long non-coding RNA derived from embryos using real-time polymerase chain reaction (PCR) or digital PCR, as well as next-generation sequencing. Various efforts are being made to use non-invasive evaluation of embryo quality (NiEEQ) to select the embryo with the best developmental competence. However, each NiEEQ method has some limitations that should be evaluated case by case. Therefore, an integrated analysis strategy fusing several NiEEQ methods should be urgently developed and confirmed by proper clinical trials.

• Nuclear Engineering and Technology
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• v.47 no.6
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• pp.678-699
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• 2015

Although the harsh space environment imposes many severe challenges to space pioneers, space exploration is a realistic and profitable goal for long-term humanity survival. One of the viable and promising options to overcome the harsh environment of space is nuclear propulsion. Particularly, the Nuclear Thermal Rocket (NTR) is a leading candidate for nearterm human missions to Mars and beyond due to its relatively high thrust and efficiency. Traditional NTR designs use typically high power reactors with fast or epithermal neutron spectrums to simplify core design and to maximize thrust. In parallel there are a series of new NTR designs with lower thrust and higher efficiency, designed to enhance mission versatility and safety through the use of redundant engines (when used in a clustered engine arrangement) for future commercialization. This paper proposes a new NTR design of the second design philosophy, Korea Advanced NUclear Thermal Engine Rocket (KANUTER), for future space applications. The KANUTER consists of an Extremely High Temperature Gas cooled Reactor (EHTGR) utilizing hydrogen propellant, a propulsion system, and an optional electricity generation system to provide propulsion as well as electricity generation. The innovatively small engine has the characteristics of high efficiency, being compact and lightweight, and bimodal capability. The notable characteristics result from the moderated EHTGR design, uniquely utilizing the integrated fuel element with an ultra heat-resistant carbide fuel, an efficient metal hydride moderator, protectively cooling channels and an individual pressure tube in an all-in-one package. The EHTGR can be bimodally operated in a propulsion mode of $100MW_{th}$ and an electricity generation mode of $100MW_{th}$, equipped with a dynamic energy conversion system. To investigate the design features of the new reactor and to estimate referential engine performance, a preliminary design study in terms of neutronics and thermohydraulics was carried out. The result indicates that the innovative design has great potential for high propellant efficiency and thrust-to-weight of engine ratio, compared with the existing NTR designs. However, the build-up of fission products in fuel has a significant impact on the bimodal operation of the moderated reactor such as xenon-induced dead time. This issue can be overcome by building in excess reactivity and control margin for the reactor design.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.9B
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• pp.1098-1107
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• 2011

As recent integration of wire and wireless networks and the convergence of telecommunications and broadcasting, uniform and standardized by the broadcasting operators of existing stations to provide 4A(Any-time, Any-where, Any-device, Any-contents) services for the next-generation of multimedia services research is being progressed. Demand for theses next-generation multimedia services to ensure video compression coding technology, as well as mobility, ability to operation a variety of devices, characteristics and performance of user network and the status and conditiion, user preferences and context-awareness based on the technology has an interest in technical studies. In this paper, the current internet environment, SVC(Scalable Video Coding) encoded by a mixture of multicast and overlay multicast transmission technology for broadcasting services by designing and efficient multimedia broadcasting system is proposed. In addition, ACK-Aow Optimization by overlay multicast scheme existing tree-based overlay multicast, and by comparing the effectiveness of the proposed algorithm is demonstrated.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.684-686
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• 2014

It is difficult to effectively search and data management due to the increasing number of web is now. While Semantic Web technologies and the development of next-generation wepin this as a way to overcome them, and monopolize the domestic utilization is not overwhelming introduction to the Semantic Web technology is being used in existing search engines. This causes the development of the Semantic Web is becoming slower, and reluctant to use the Semantic Web users who use search engines as well. In this paper, compared to the currently used web and the next generation of the web, and why utilization is low compared to the search engine you are using an existing Web technology that uses the Semantic Web technology is a search engine, what research was that the inefficient because, as a RDF-based Semantic suggest how to improve the efficiency solved by designing the web.

• Proceedings of the Korea Contents Association Conference
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• 2003.05a
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• pp.277-290
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• 2003

Recently, digital contents have become increasingly perceived as a core aspect of national development, and as such their generation and widespread promotion is being now pursued on a global basis, as federal governments move to assist corporations in the realization ofconsistent industrial development. Efforts are also being made to seek avenues for the paid use of qualitatively excellent contents, instead of relying upon traditional methods of free-of-charge provision. International corporations as well as governments are committing themselves to the search for a more developed approach to paid contents. In this report, the role of public institutions in executing plans and promotional strategies for the charging and development of the contents industry is examined. In particular, the case of paid contents is analyzed in relation to the Korea Institute of Science and Technology Information (KISTI), which is assigned the task of contents distribution to the general public in its capacity as a public information service institution, not as a profit-oriented general corporation.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.28 no.2
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• pp.189-196
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• 2010

Spatial information and smart phone technology have made innovative improvement of daily life. Spatial and geographic information are in practice for various applications. Especially, spatial information along with information and telecommunication technology could create new contents for providing services for convenient daily life. Spatial information technology, recently, is not only for acquiring location and attribute data but also providing tools to extract information and knowledge systematically for decision making. Various indoor applications have emerged in accordance with demands on daily GIS(Geographic information system). This paper aims for applying spatial information technology to support decision-making in shopping. The main contents include product database, optimal path search, shopping time expectation, automatic housekeeping book generation and analysis. Especially for foods, function to analyze information of the nutrition facts could help to improve dietary pattern and well-being. In addition, this system is expected to provide information for preventing overconsumption and impulse purchase could help economical and effective purchase pattern by analyzing propensity to consume.

• Journal of Korean Society of Rural Planning
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• v.28 no.4
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• pp.55-67
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• 2022

In this study, the village development promotion system was reorganized for Gimhae-si, and improvement plans and post-operation management plans were prepared through expert surveys. Through the Village Development Project, the landscape and environment of the village were improved, and the village and residents were positively changed. The Village Development Project laid the foundation for regional revitalization, giving the next generation hope for the sustainable development of the village. While maintaining the framework of the existing Rural Development Projects guidelines through case analysis of other regions, we operate educational programs for each stage by reflecting regional characteristics, and utilize and communicate with intermediate support organizations, systematically operate, and actively intervene by Eup·Myeon administration. In addition, as a follow-up management program, various follow-up management programs were being operated, such as support for capacity building such as consulting, as well as facility maintenance and support for village managers. As a result of the expert survey to review the adequacy of the improvement plan, the improvement plan derived from the overall average of 4.28 points and the standard deviation of 0 to 0.94 points for the process is judged to be appropriate. In particular, the item of 'self-reliance stage follow-up management' was very important as all experts responded with 5 points. By establishing the village development performance goals, we tried to check whether the qualitative/quantitative goals were achieved by year, and to secure quantified status data in response to changes such as resetting performance goals or adding new performance indicators. In this study, in order to improve the capacity to achieve regional development in response to the rural agreement, we prepared our own sustainable village development promotion system, governance establishment, and follow-up management plan. In addition, it is expected to be used as a reference material for the selection of new districts and the follow-up management of completed districts by establishing the village development goals.

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 2008.03a
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• pp.79-88
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• 2008

Since the hydraulic fracturing field testing method was introduced first to Korean geotechnical engineers in 1994, there have been lots of progresses in a hardware system as well as an interpretation tool. The hydrofracturing system of first generation was the pipe-line type, so it was not easy to handle. It had been modified to a wire-line system at their second generation. It was more compact one but it also needed an additional air-compressor. Our current system is much more compact and operated by all-in-one system, so it doesn't need an additional air-compressor. With a progress in a hardware system, the software for analyzing the in-situ stress regime has also been progressed. For example, the shut-in pressure, which is the most ambiguous parameter to be obtained from hydrofracturing pressure curves, can now be acquired automatically from the various methods. While the hardware and software for hydrofracturing tests are being developed during the last decade, the author could accumulate the field test results which can cover the almost whole area of South Korea. Currently these field data are used widely in a feasibility study or a preliminary design step for tunnel construction in Korea. Regarding the difficulties in a site selection and a test performance for the in-situ stress measurement at an off-shore area, the in-situ stress regime obtained from the field experiences in the land area can be used indirectly for the design of a sub-sea tunnel. From the hydrofracturing stress measurements, the trend of magnitude and direction of in-situ stress field was shown identically with the geological information in Korea.