• Polymer(Korea)
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• v.32 no.5
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• pp.470-477
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• 2008

Core shell binder of organic/organic pair that has two different properties within a particle were prepared by a step emulsion polymerization of methacrylate (MMA), styrene (St), ethyl acrylate (EA), butyl acrylate (BA), and 2-HEMA by using an water soluble initiator(APS) in the presence of an anionic surfactant (SDBS). Unwoven tensile strength of the core shell binder after processing and measuring the PSt/PMMA/2-HEM core shell with the binder is a value represents the highest was $10.75\;kg_f$/2.5cm, elongation measurements PEA/PBA core shell binder showed the highest value was 120.00%. In conclusion, using the core shell binders were able to control the mechanical properties such as tensile strength and elongation.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.6
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• pp.445-452
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• 2014

This paper discusses the multifrontal direct solution method with out of core storage for large scale structural analysis in a limited computing resource. Large scale structural analysis requires huge amount of memory space and computation, so out of core solution method is needed in limited computing resource. In this research, out of core multifrontal solution algorithm which utilize the small size of physical memory and minimize the amount of access of low speed out of core storage is introduced. Three ideas, which are stack space in lower trianglar part of square factorization matrix, inverse stack data structure and selective data caching and recovery by data block size, are proposed.

• Archives of Pharmacal Research
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• v.29 no.8
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• pp.712-719
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• 2006

In this study, we prepared core-shell type nanoparticles of a poly(DL-lactide-co-glycolide) (PLGA) grafted-dextran (DexLG) copolymer with varying graft ratio of PLGA. The synthesis of the DexLG copolymer was confirmed by $^1H$ nuclear magnetic resonance (NMR) spectroscopy. The DexLG copolymer was able to form nanoparticles in water by self-aggregating process, and their particle size was around $50\;nm{\sim}300\;nm$ according to the graft ratio of PLGA. Morphological observations using a transmission electron microscope (TEM) showed that the nanoparticles of the DexLG copolymer have uniformly spherical shapes. From fluorescence probe study using pyrene as a hydrophobic probe, critical association concentration (CAC) values determined from the fluorescence excitation spectra were increased as increase of DS of PLGA. $^1H-NMR$ spectroscopy using $D_2O$ and DMSO approved that DexLG nanoparticles have core-shell structure, i.e. hydrophobic block PLGA consisted inner-core as a drug-incorporating domain and dextran consisted as a hydrated outershell. Drug release rate from DexLG nano-particles became faster in the presence of dextranase in spite of the release rate not being significantly changed at high graft ratio of PLGA. Core-shell type nanoparticles of DexLG copolymer can be used as a colonic drug carrier. In conclusion, size, morphology, and molecular structure of DexLG nanoparticles are available to consider as an oral drug targeting nanoparticles.

• Journal of Advanced Technology Convergence
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• v.1 no.1
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• pp.7-13
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• 2022

In this study, we prepared the functionalized Shampoo with three-type functionalized microcaples which were synthesized by microcapsulation, respectively. In detail, the functionalized microcapsule was included such as (1) the functionalized microcapsule with core-menthol and shell-melamine resin and (2) the functionalized microcapsule with core-menthol and shell-lecithin, and (3) the functionalized microcapsule with core-cinnamon oil and shell-lecithin, respectively. The size and morphology of the prepared microcapsules was evaluated via Optical Microscopy (OM), Scanning Electron Microscopy (SEM) and Dynamic Light Scattering (DLS). From these results, the prepared microcapsules with size of 0.1~0.2 ㎛ and spherical morphology was confirmed. Furthermore, we applied the prepared Shampoo to treat hair. As results we confirmed that the scalp temperature was decreased about 3~4 ℃ compared to no treatment. This result may be considered that the core compounds are vaporize when the functionalized Shampoo is treated on scalp. We will determine the change of scalp pore, diameter of hair, and etc during treatment of the functionalized Shampoo.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.17 no.3
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• pp.166-175
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• 2024

In this paper, the Window-Masking Method and HAT (Hardware Attached Top) CPU SoM (System on Module) are used to improve the performance and reduce the weight of the MANET (Mobile Ad-hoc Network) network synchronization system using time division redundancy. We propose converting it into a RISC-V based soft-core MCU and mounting it on an FPGA, a hardware accelerator. It was also verified through experiment. In terms of performance, by applying the proposed technique, the synchronization acquisition range is from -50dBm to +10dBm to -60dBm to +10dBm, the lowest input level for synchronization is increased by 20% from -50dBm to -60dBm, and the detection delay (Latency) is 220ns. Reduced by 43% to 125ns. In terms of weight reduction, computing resources (48%), size (33%), and weight (27%) were reduced by an average of 36% by replacing with soft-core MCU.

• Proceedings of the Korean Nuclear Society Conference
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• 1997.05a
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• pp.495-501
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• 1997

A preliminary and parametric sensitivity study on recriticality risk of fast reactor cores after a hypothetical total core meltdown accident was performed. Only neutronic aspects of the accident were considered, independent of the accident scenario, and efforts were made to estimate the quantity of molten fuel which must be ejected out of the core to assure a sub-critical state after the accident. Two types of parameters were examined : characteristic parameters of molten core such as geometry, molten pool type (homogenized or stratified), fuel temperature, environment, and relative parameters to normal core such as core size(small or large), and fuel type (oxide, nitride, metal). The first type of parameters was found to intervene more directly in the recriticality risk than the second type of parameters.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08b
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• pp.1551-1554
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• 2007

To overcome defect due to large surface of nanoparticle, a redispersible Eu doped $LnPO_4:LnPO_4$ core/shell nanoparticles were prepared in a highboiling coordinating solvent. The particle size of the synthesized core/shell nanophosphors was estimated to be about 8 nm by TEM. In this core/shell nanoparticle, the concentration of Eu ion was optimized on the basis of the emission intensity under UV ray excitation. Also, the PL properties of the nanophosphors have been compared with those of the $LnPO_4:Eu$ nanoparticles.

• Advanced Composite Materials
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• v.16 no.1
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• pp.11-30
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• 2007

Since delamination often propagates at the interfacial layer between a surface skin and a foam core, a crack arrester is proposed for the suppression of the delamination. The arrester has a semi-cylindrical shape and is arranged in the foam core and is attached to the surface skin. Here, energy release rates and complex stress intensity factors are calculated using finite element analysis. Effects of the arrester size and its elastic moduli on the crack suppressing capability are investigated. Considerable reductions of the energy release rates at the crack tip are achieved as the crack tip approached the leading edge of the crack arrester. Thus, this new concept of a crack arrester may become a promising device to suppress crack initiation and propagation of the foam core sandwich panels.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.33 no.1
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• pp.64-71
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• 2009

In this paper, a study on low-velocity impact response of honeycomb sandwich panels was done for the changes of impact location and core fabrication angles. The test specimens were made of glass/epoxy laminate facesheet and aluminum honeycomb core. Square samples of 100mm and 100mm sides were subjected under low-velocity impact loading using instrumented testing machine at three energy levels. Impact parameters like maximum force, time to maximum force, deflection at maximum force and absorbed energy were evaluated and compared for the changes of impact location and core fabrication angle. The impact damage size were measured at facesheet surface by 3-Dimensional scanner. Also, sandwich specimens after impact test were cut to analyse the failure mode.

• Electrical & Electronic Materials
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• v.10 no.8
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• pp.813-818
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• 1997

In this study the thin film air core and magnetic core inductors consisting of planar coil and/or CoNbZr amorphous magnetic layers on a Si substrate were fabricated as spiral type by using rf magnetron sputtering and wet etching methods. The etchant solution was achieved by iron chloride solution(17.5 mol%) mixed with HF (20 mol%) during 150 sec which etched Cu films and CoNbZr/Cu/CoNbZr multi-layer films. They were about 10${\mu}{\textrm}{m}$ of thickness and 10$\times$10 mm$^2$of size. The properties of thin film magnetic core inductor were 400 nH of Q value at 10 MHz and the resonance frequency was about 300 MHz.