• Journal of the Korean Society of Visualization
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• v.9 no.2
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• pp.16-20
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• 2011

This paper presents a fabrication method of microcapsules encapsulating fluorescent nanoparticles sensitive to an organic liquid, which is potentially applicable to the encapsulation of protein, cell and drug. It uses the supra-molecular self-assembly of a block copolymer at the interface of the stable and controllable droplets of water suspended with fluorescent nanoparticles and the polymer solved organic. The size and uniformity of the microcapsules were examined for the various polymer concentrations by using SEM image analysis. The maximum standard deviation of the produced microcapsules of less than 3.5% was obtained from the microcapsules produced from the same conditions. The inclusion of fluorescent nanoparticles was visualized in the fluorescence microscope and by using TEM image. It is shown that this fabrication method can provide the uniform size microcapsules with a higher inclusion.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.267.1-267.1
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• 2013

In modern science and technology, the organization of building blocks, such as spherical particles and zeolite, is important to form a nanostructure. So, it is essential to develop methods for organizing them into large scale for many precise applications. Up to now, reflux and stirring is widely used method for organization of colloidal particles. However, because this method is hard to organize building block with high coverage and uniform orientation, it is necessary to research another method. In this work, we synthesized spherical silica particles using St$\"{o}$ber method and organized them on the glass which is coated with 3-chloropropyltrimethoxysilane (CP-TMS) and polyethyleneimine (PEI) using Sonication method. Although spherical silica particles are difficult to attach on the glass due to their small attachment site, we improved this problem by coating PEI. We introduced two mode of reaction promotion, sonication (SO) and sonication with stacking between the bare glass (SS), and investigated degree of coverage (DOC) and degree of close packing (DCP).

• Journal of the Society of Naval Architects of Korea
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• v.43 no.1 s.145
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• pp.68-74
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• 2006

The welding distortion of a hull structure in the shipbuilding industry is inevitable at each assembly stage. This geometric inaccuracy caused by the welding distortion tends to preclude the introduction of automation and mechanization and needs the additional man-hours for the adjusting work at the following assembly stage. To overcome this problem, a distortion control method should be applied. For this purpose, it is necessary to develop an accurate prediction method which can explicitly account for the influence of various factors on the welding distortion. The validity of the prediction method must be also clarified through experiments. For the purpose of reducing the weld-induced bending deflection, this paper proposes the mechanical tensioning method (MTM) as the optimum distortion control method. The validity of this method has been substantiated by a number of numerical simulations and actual measurements.

• Bulletin of the Korean Chemical Society
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• v.34 no.6
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• pp.1800-1808
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• 2013

Dual-responsive amphiphilic block copolymers were synthesized by combining enzymatic ring-opening polymerization (eROP) of ${\varepsilon}$-caprolactone (CL) and ATRP of N,N-dimethylamino-2-ethyl methacrylate (DMAEMA). The obtained block copolymers were characterized by gel permeation chromatography (GPC), $^1H$ NMR and FTIR-IR. The critical micelle concentration (CMC) of copolymer was determined by fluorescence spectra, it can be found that with hydrophilic block (PDMAEMA) increasing, CMC value of the polymer sample increased accordingly, and the CMC value was 0.012 mg/mL, 0.025 mg/mL and 0.037 mg/mL for $PCL_{50}$-b-$PDMAEMA_{68}$, $PCL_{50}$-b-$PDMAEMA_{89}$, $PCL_{50}$-b-$PDMAEMA_{112}$, $PCL_{50}$-b-$PDMAEMA_{89}$ was chosen as drug carrier to study in vitro release profile of anti-cancer drug (taxol). The temperature and pH dependence of the values of hydrodynamic diameter (Dh) of micelles, and self-assembly of the resulting block copolymers in water were evaluated by dynamic light scattering (DLS). The result showed that with the temperature increasing and pH decreasing, the Dh decreased. Drug-loaded nanoparticles were fabricated using paclitaxel as model. Transmission electron microscopy (TEM) and atomic force microscopy (AFM) had been explored to study the morphology of the hollow micelles and the nanoparticles, revealing well-dispersed spheres with the average diameters both around 80 nm. In vitro release kinetics of paclitaxel from the nanoparticles was also investigated in different conditions (pH and temperature, etc.), revealing that the drug release was triggered by temperature changes upon the lower critical solution temperature (LCST) at pH 7.4, and at $37^{\circ}C$ by an increase of pH.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.18 no.6A
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• pp.51-61
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• 2008

This paper suggests a new way to implement high speed AES on Intel Core2 processors and AMD Athlon64 processors, which are used all over the world today. First, Core2 Processors of EM64T architecture's memory-access-instruction processing efficiency are lower than calculus-instruction processing efficiency. So, previous AES implementation techniques, which had a high rate of memory-access-instruction, could cause memory-bottleneck. To improve this problem we present the partial round key techniques that reduce the rate of memory-access-instruction. The result in Intel Core2Duo 3.0 Ghz Processors show 185 cycles/block and 2.0 Gbps's throughputs in ECB mode. This is 35 cycles/block faster than bernstein software, which is known for being the fastest way. On the other side, in AMD64 processors of AMD64 architecture, by removing bottlenecks that occur in decoding processing we could improve the speed, with the result that the Athlon64 processor reached 170 cycles/block. The result that we present is the same performance of Matsui's unpublished software.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.885-888
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• 2005

In this study, we designed an ARM9 compatible RISC microprocessor using VHDL. The microprocessor was designed to support Harvard architecture with separate instruction cache and data cache. The state machine was optimized for multi-cycle instructions. In addition, a data forwarding mechanism was adopted to reduce the stall cycles due to data hazards. Assembly programs were up-loaded into a ROM block for system-level simulation. Proper operation of the designed microprocessor was confirmed by investigating the contents of the internal registers as well as the RAM block. Futhermore, the simulation results clearly indicated that the operation speed of the processor designed in this study is enhanced by reducing the execution cycles required for multiplication related instructions.

• Proceedings of the KSME Conference
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• 2001.06d
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• pp.390-395
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• 2001

Cooling characteristics using convection and conduction heat transfer in a parallel channel with extruding heat sources are studied numerically. A two-dimensional model has been developed for numerical prediction of transient, compressible, viscous, laminar flow, and conjugate heat transfer between parallel plates with uniform block heat sources. The finite volume method is used to solve this problem. The considered assembly consists of two channels formed by two covers and one PCB which has three uniform heat source blocks. Five different cooling methods are considered to find efficient cooling method in a given geometry and heat source. The velocity and temperature fields, local temperature distribution along surface of blocks, and the maximum temperature in each block are obtained.

• Journal of the Korea Furniture Society
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• v.16 no.1
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• pp.1-8
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• 2005

This experiment was carried out to investigate the gluing characteristics of poly vinyl acetate emulsion adhesive(PVAc) on the Cryptomeria japonica laminated boards. This sample trees are major planting species and have been planted in southern district for a long time. The optimum gluing conditions for laminated board were summarized as follows; the amount of spreading glue, assembly time, clamping pressure, and clamping time for PVAc resin were $200g/m^2$, 10min., $5kg/cm^2$, and 6hrs., respectively, and the relative formulae between extension ratio(x) and block shear strength(y) was $y=-9.6x+85.2(R^2=0.95)$.

• International Journal of Naval Architecture and Ocean Engineering
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• v.2 no.3
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• pp.171-176
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• 2010

This paper proposes the application of sensor technology to assemble ship blocks efficiently. A sensor-based monitoring system is designed and implemented to improve shipbuilding productivity by reducing the labor cost for the adjustment of adequate positioning between ship blocks during pre-erection or erection stage. For the real-time remote monitoring of relative distances between two ship blocks, sensor nodes are applied to measure the distances between corresponding target points on the blocks. Highly precise positioning data can be transferred to a monitoring server via wireless network, and analyzed to support the decision making which needs to determine the next construction process; further adjustment or seam welding between the ship blocks. The developed system is expected to put to practical use, and increase the productivity during ship blocks assembly.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.58 no.1
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• pp.67-71
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• 2009

This research is a new structure of the semiconductor substrate heating apparatus in which the assembly and expansion are possible. The fast thermo-responsive according to the direct heating structure of the heating plate layer adhering closely to the floor side of a substrate and the fast heat loss minimization can be accomplished. Moreover, the contact area of the sheath heater, which is the heating plate layer built-in heating apparatus, is increased, so that it has more heating valid area. There is no problem with the deformation interpreted in the state where it assembles the block of a several of the simulation result structure, the safety, and the stress. In addition, it is confirmed that building a large-size heating block is possible since the temperature deflection of the manufactured plate is lower than the standard value.