• Journal of Astronomy and Space Sciences
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• v.31 no.1
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• pp.67-72
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• 2014

The next generation small satellite-1 (NEXTSat-1) program has been kicked off in 2012, and it will be launched in 2016 for the science missions and the verification of space core technologies. The payloads for these science missions are the Instrument for the Study of Space Storms (ISSS) and NIR Imaging Spectrometer for Star formation history (NISS). The ISSS and the NISS have been developed by Korea Advanced Institute of Science and Technology (KAIST) and Korea Astronomy and Space science Institute (KASI) respectively. The ISSS detects plasma densities and particle fluxes of 10 MeV energy range near the Earth and the NISS uses spectrometer. In order to verify the spacecraft core technologies in the space, the total of 7 space core technologies (SCT) will be applied to the NEXTSat-1 for space verification and those are under development. Thus, the operation modes for the ISSS and the NISS for space science missions and 7 SCTs for technology missions are analyzed for the required operation time during the NEXTSat-1's mission life time of 2 years. In this paper, the operational concept of the NEXTSat-1's science missions as well as the verification of space core technologies are presented considering constraints of volume, mass, and power after launch.

• Nuclear Engineering and Technology
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• v.38 no.1
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• pp.1-10
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• 2006

The interaction and mixing of high-temperature melt and water is the important technical issue in the safety assessment of water-cooled reactors to achieve ultimate core coolability. For specific advanced light water reactor (ALWR) designs, deliberate mixing of the core-melt and water is being considered as a mitigative measure, to assure ex-vessel core coolability. The paper provides the background of past experiments as well as key fundamentals that are needed for melt-water interfacial transport phenomena, thus enabling the development of innovative safety technologies for advanced LWRs that will assure ex-vessel core coolability.

• Nuclear Engineering and Technology
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• v.55 no.10
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• pp.3639-3647
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• 2023

This paper defines a 3D full core neutronics benchmark which is based on the NuScale small modular reactor (SMR) concept. The paper provides a detailed description of the NuScale-like core, a list of expected outputs, and a reference solution to the benchmark exercises obtained with the Monte Carlo code Serpent. The benchmark was developed in the framework of the Euratom McSAFER project and can be used for verification of computational chains dedicated to 3D full-core neutronics simulations of water cooled SMRs. The paper is supplemented with a digital data set to ease the modeling process.

• The KSFM Journal of Fluid Machinery
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• v.17 no.6
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• pp.104-108
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• 2014

The recent Fukushima nuclear power plant accidents shows that the core make up at high RCS pressure condition is very important to prevent core melting. The core make up flow at high pressure condition should be driven by gravity force or passive forces because the AC-powered safety features are not available during a Station Black Out (SBO) accident. The reactor Coolant System (RCS) mass inventory is continuously decreased by releasing steam through the pressurizer safety valves after reactor trip during a SBO accident. The core will be melted down within 2~3 hours without core make up action by active or passive mode. In the new design concept of a Hybrid Safety Injection Tank (Hybrid SIT) both for low and high RCS pressure conditions, the low pressure nitrogen gas serves as a charging pressure for a LBLOCA injection mode, while the PZR high pressure steam provides an equalizing pressure for a high pressure injection mode such as a SBO accident. After the pressure equalizing process by battery driven initiation valve at a high pressure SBO condition, the Hybrid SIT injection water will be passively injected into the reactor downcomer by gravity head. The SBO simulation by MARS code show that the core makeup injection flow through the Hybrid SIT continued up to the SIT empty condition, and the core heatup is delayed as much.

• Journal of Korean Medicine for Obesity Research
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• v.7 no.2
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• pp.77-84
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• 2007

Obejectives : Slow-motion strengthening trainings build up muscles better than any other type of training, these exercises focus on balancing and strengthening the muscles in the anatomical center of the body - the core - which includes the back, hip and abdominal muscles. Methods : We had a concept of 'core', and compared core muscles with 12 meridian tendino-musculature based on Thomas Myers' myofascial meridian. Results : It has been suggested that the core muscles correspond to meridians of foot- three Yin and foot- three Yang. The study of core muscles strengthening exercise and movement therapy is requred.

• Journal of Korea Foundry Society
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• v.28 no.4
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• pp.166-169
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• 2008

This study deals about the development of fusible core with low melting temperature by addition of ceramic particles. A new concept of salt core was introduced to produce an integrated casting part having a complicated inner shape or requiring under-cut in high pressure die casting or squeeze casting process. The mechanical properties of fusible core were improved due to the addition of ceramic particles which helped to produce fine microstructure. The new technology for the preparation of new fusible core materials which possess high compression strength was established. Addition of ceramics particles increased the mechanical properties of fusible core materials. There was an increasing relationship between percentage of ceramic particles and mechanical strength was existed up to 60%.

• Journal of the Korean Professional Engineers Association
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• v.34 no.5
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• pp.18-24
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• 2001

This Seoul World Cup Stadium is designed not only for FIFA's Football Game. This stadium would be a very huge multi-use urvan structure as a core of new developing west seoul. Architect's basic design concept is based on the combination of traditional korean symbolic form and ultra mordern high-tech.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.540-545
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• 2001

In case of small motors, coil bundle occupies a large portion of stator in view of mass and volume as well as dynamics. It is observed through modal test on the stator of an IPM BLDC (interior permanent magnet brushless direct current) motor that coil bundle wound on the stator core causes the first and second natural frequencies to decrease by about 20-30% compared with those of bare stator. Especially the third natural frequency is newly observed below 3 KHz, which is not observed on the bare stator. It is found that at the third mode the end-coil and the core vibrate out of phase in radial direction. In this paper, the stator is dynamically modeled in terms of the core and the coil bundle consisting of the end-coil and the slot coil based on the above observations for the prediction of dynamic properties. The core can easily be modeled using finite element method with its actual material properties and geometric shape. The concept of equivalent bending stiffness is used for modeling of the end-coil so that predictions may match with the measured natural frequencies for the end-coil cut out of the stator. Although the same concept can be applied to the slot coil, separation of the slot coil from the stator is impractical. Therefore, equivalent bending stiffness of the slot coil is determined through iterative comparisons with the measurements of natural frequencies of the stator with the slot coil in it.

• Korean Institute of Interior Design Journal
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• v.23 no.1
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• pp.88-95
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• 2014

This study intended arousal of other viewpoints that deal with and understand spaces and shapes, by describing the concept of 'dimensions' into visual patterns. Above all, the core concept of spatial dimensions was defined as 'expandability'. Then, first, the 'golden ratio', 'Fibonacci sequence', and 'fractal theory' were defined as elements of each dimension by stage. Second, a 'unit cell' of one dimension as 'minimum unit particles' was set. Next, Fibonacci sequence was set as an extended concept into two dimensions. Expansion into three dimensions was applied to the concept of 'self-similarity repetition' of 'Fractal'. In 'fractal dimension', the concept of 'regularity of irregularity' was set as a core attribute. Plus, Platonic solids were applied as a background concept of the setting of the 'unit cell' from the viewpoint of 'minimum unit particles'. Third, while 'characteristic patterns' which are shown in the courses of 'expansion' of each dimension were embodied for the visual expression forms of dimensions, expansion forms of dimensions are based on the premise of volume, directional nature, and concept of axes. Expressed shapes of each dimension are shown into visually diverse patterns and unexpected formative aspects, along with the expression of relative blank spaces originated from dualism. On the basis of these results, the 'unit cell' that is set as a concept of theoretical factor can be defined as a minimum factor of a basic algorism caused by other purpose. In here, by applying diverse pattern types, the fact that meaning spaces, shapes, and dimensions can be extracted was suggested.

• The Journal of Korean Physical Therapy
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• v.26 no.5
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• pp.351-357
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• 2014

Purpose: The purpose of this study was to investigate level of functioning in patients with stroke using Modified Bathel Index (MBI), World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0), and ICF core-set for stroke. Methods: Sixty-four patients with stroke were recruited for this study from nine medical institutes. The ICF core-set for stroke, WHODAS 2.0, and MBI were used to collect subjects' functional levels. ICF core-set was employed here as a standard frame to observe multi-dimension of functioning, that is physiological bodily function, activity and participation (AP) in daily life, and current environmental factors (EF) in patients with stroke. WHODAS 2.0 and MBI were also used in order to have a specific functioning level for subjects. The linkage of each item in WHODAS 2.0 and MBI into the ICF core-set for stroke was examined. Pearson correlation coefficient was used for analysis of their relationships. Results: Functioning level of participants showed moderate resulting from MBI and WHODAS 2.0 ($73.48{\pm}22.27$ and $35.55{\pm}12.53$, respectively). Strong relationship was observed between ICF core-set and WHODAS 2.0, and with MBI. Each item of disability scales was obtained its linkage into ICF in the domain of AP. However, lack of correlation between MBI and ICF in the domain of EF was found due to absence of related factors. Conclusion: MBI was found to be linked mainly into ICF in the domain of AP and to have limited linkage into EF. Therefore, it should be suggested that the ICF concept frame should be used as a multi-dimensional approach to patients with stroke.