• Advances in nano research
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• v.5 no.3
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• pp.253-260
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• 2017

We report a simple eco-friendly process for the synthesis of gold nanoparticles (AuNPs) using aqueous extract from Coffea Arabica fruit. The formation of AuNPs was confirmed using absorption spectroscopy and scanning electron microscopy images. FT-IR analysis demonstrates the major functional groups present in Coffee Arabica fruit extract before and after synthesizing AuNPs. The Face Center Cubic (FCC) polycrystalline nature of these particles was identified by X-Ray diffraction (XRD) analysis. Taking into account the contribution of the biomass surrounding the AuNPs, dynamic light scattering (DLS) results revealed an average particle size of ~59 nm.

• Proceedings of the KSR Conference
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• 2004.06a
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• pp.352-357
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• 2004

In this study. the effects of combined environmental factors on mechanical and thermal analysis properties of graphite/epoxy composites were evaluated through a 2.5KW accelerated environmental aging tester. Environmental factors such as temperature. moisture, and ultraviolet were considered. A xenon-arc lamp was utilized for ultraviolet light. and exposure times of up to 3000 hours were applied. Several types of specimens - tensile, bending, and shear specimens those are warp direction and fill direction were used to investigate the effects of environmental factors on mechanical properties of the composites. The glass fabric $\sharp$650/AP300 was used for the fabrication of specimens. Mechanical degradations for tensile, bending and shear properties were evaluated through a UTM. Also. storage shear modulus. loss shear modulus, and tan $\delta$ were measured as a function of exposure times through a dynamic mechanical analyzer. Finally exposed surfaces of the composites were examined using II scanning electron microscope.

• Proceedings of the KSRS Conference
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• v.1
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• pp.135-137
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• 2006

HY-2, the China's satellite for oceanic dynamic environment measurement, is planed to be launched around 2010. The main payloads of HY-2 include a dual-frequency radar altimeter equipped with a three-band nadir-looking radiometer for atmospheric delay correction, a Ku-band radar scatterometer, and a five-band scanning radiometer. This presentation outlines the specifications, parameters, and design of the HY-2 radar altimeter and scatterometer.

• Journal of Welding and Joining
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• v.24 no.2
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• pp.57-63
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• 2006

In this study, the curing kinetics and thermal degradation of underfill were investigated using differential scanning calorimetry (DSC) and thermo gravimetry analysis (TGA). The mechanical and thermal properties of underfill were characterized using dynamic mechanical analysis (DMA) and thermo-mechanical analysis (TMA). Also, we presented on underfill dispensing process using Prostar tool. The non-isothermal DSC scans at various heating rates, the exothermic reaction peak became narrower with increasing the heating rate. The thermal degradation of underfill was composed of two processes, which involved chemical reactions between the degrading polymer and oxygen from the air atmosphere. The results of fluidity phenomena were simulated using Star CD program, the fluidity of the underfills with lower viscosity was faster.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2002.10a
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• pp.33-37
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• 2002

Recently, composites have been widely applied in the sporting goods, automobile, aerospace industry. As the use of advanced composites increase, specific techniques have been developed to repair damaged composite structures. In order to repair the damaged part, it is required that the material in the damaged area be removed first by utilizing the proper method, and prepreg be laid up in the area and cured under vacuum using the vacuum bagging materials. In curing process, either in an oven or autoclave is to be delamination can be occurred in the sound areas during and/or after the exposure to the elevated curing temperature in case that the repair process is repeated. Therefore, this study was conducted to evaluate the degree of degradation of properties of the cured parts and how it affects to the delamination phenomenon between laminated skin and honeycomb core.

• 제어로봇시스템학회:학술대회논문집
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• 1995.10a
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• pp.127-130
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• 1995

Fuzzy controllers have proven to be powerful in controlling dynamic processes where mathematical models are unknown or intractable and ill-defined. The way of improving the performance of a fuzzy controller is based on making up rules, constructing membership functions, selecting a defuzzification method and adjusting input-output scaling factors. But there are many difficulties in tuning those to optimize a fuzzy controller. So, in this paper, we propose the look-up table based self-orgenizing fuzzy controller (LSOFC) which optimizes look-up values resulting from the above fuzzy processes. We use the plus-minus tuning method(PMTM), scanning the value through the processes of addition and subtraction. Simulation results demonstrate that the performance of LSOFC is far better than that of a non-tuning fuzzy controller.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.824-829
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• 2007

Mechanical and thermal analysis properties of carbon fiber/epoxy composite for train carbody were evaluated by varying with environmental factors such as ultraviolet, temperature, and moisture. Accelerated environmental aging tester was utilized for this study. Testing temperature was set to $80^{\circ}C$ and ultraviolet was obtained through xenon-arc lamp. To consider moisture, water sprayed on specimen for 18 minutes every 2 hour. All the specimens were made of CF1263/Epoxy composite. Mechanical properties such as tensile, bending, and shear properties were evaluated through a material testing system. Also, thermal analysis properties such as storage shear modulus, loss shear modulus, and tan ${\delta}$ were measured through dynamic mechanical analyzer. Finally surfaces of the composite exposed to environmental factors were examined using a scanning electron microscope. From experimental results, those properties of CF1263/Epoxy composite were shown to be slightly decreased due to environmental factors.

• Proceedings of the KIEE Conference
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• 1996.07c
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• pp.1670-1672
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• 1996

Silicone rubber composite is very suitable for insulation materials because of it's hydrophobicity, mass productivity, and design flexibility. A study of the diffusion of silicone fluid from the bulk to the surface of the silicone rubber composite using dynamic contact angle meter and scanning electron microscopy(SEM) is reported. A study of the mechanical strength of the silicone rubber composite having various silicone fluids and fluid contents is also reported. It has been found that the kind of silicone fluid affects the diffusion rate of the silicone fluid from the bulk to the surface of the silicone rubber composite after artificial pollution.

• The Journal of the Korean life insurance medical association
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• v.31 no.1
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• pp.34-36
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• 2012

Lung cancer such as small cell lung cancer(SCLC) and non small cell lung cancer(NSCLC) have high mortality rate, so, we insurance doctors have little interest in their risk. But nowadays there's a lot of development in targeted therapy of NSCLC. Screening by CT scanning and early resection strategy also shows better prognosis. It is helpful for underwriters and insurance doctors to review the current development of targeted therapy of NSCLC and estimation of extra-risk of early lung cancer. The preferred treatment option for patients whose tumors contain EGFR-activating mutations are one of the EGFR-directed tyrosine kinase inhibitors, such as gefitinib or erlotinib. In patients with NSCLC whose tumors harboured an ALK rearrangement, there was 61% objective response rate to crizotinib in the phase 1 study. The median survival progression-free survival was 10 months. Mortality analysis of early lung cancer who were detected by CT screening, MR of 105% and EDR of 1‰ were calculated.

• Journal of the Korean Society of Tobacco Science
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• v.7 no.2
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• pp.169-178
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• 1985

In the previous paper, the kinetics of cellulose were described. In this study, the ability of some additives to act as a flame promoter for cellulose was investigated using dynamic thermogravimetry and differential scanning calorimetry. The treated cellulose was thermally decomposed through the two model as previously noted with the untreated cellulose. The first step was associated with the flaming combustion of volatile material released in the fraunentation process and the second was caused by the glowing combustion of carbonaceous residue. The first group of the additives, which could be divided into two groups by the pyrolytic mechanism of cellulose, appeared to catalyze the fragmentation, maximizing the degradation to produce tarry products, with gaseous flammable substrate. The heat evolved in flaming combustion mode was increased significantly by the treatment of the cellulose retained 1-5% of the first group additives.