• Journal of radiological science and technology
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• v.29 no.2
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• pp.53-56
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• 2006

The purpose of the present study is to find ways to reduce the quantity of indoor radon contamination. The study was done from July, 2005 until December, 2005. It was found out that the easiest and most effective way to do that is to open the windows as often as possible and let the indoor air flow outside. When it is not possible to ventilate a room, the indoor radon contamination quantity can reduced by providing activated charcoal in the room. It has been proved that activated charcoal can absorb the room in the air. We need more activated charcoal in proportion to the size of the room. A further research is needed to investigate the amount of activated charcoal that will work most effectively.

• Polymer(Korea)
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• v.32 no.6
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• pp.598-602
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• 2008

In this study we prepared crosslinked separators with the improved thermal stability by irradiating a commercial polyethylene (PE) separator for lithium secondary battery with an electron beam, and the thermal and mechanical properties of the prepared separators were evaluated as a function of the absorption dose. The thermal shrinkage of electron beam irradiated separator was decreased with increasing absorption dose. As a result of the shutdown behavior using an AC impedance, it was observed that the irradiated separator had the better shutdown function than the unirradiated separator. The modulus of the irradiated separator was enhanced as the absorption dose was increased, while the tensile strength and the break elongation of the irradiated separator were decreased.

• Membrane Journal
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• v.25 no.6
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• pp.515-523
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• 2015

While commercial polystyrene-based ion exchange membranes have simple manufacturing processes, they also possess poor durability due to their brittleness. Poly(ethylene glycol)methyl ether methacrylate with hydrophilic side chains of poly(ethylene glycol) was used as a co-monomer to make the membranes have improved flexibility. Hydrophilicity/hydrophobicity of the anion exchange membranes were able to be adjusted by varying the chain lengths of the poly(ethylene glycol). For the preparation of the anion exchange membranes, a porous PE substrate was immersed into monomer solutions and thermally polymerized. The prepared membranes were subsequently reacted with trimethylamine to produce anion exchange functional groups, Quaternary ammonium salts. The prepared pore-filled anion exchange membranes were evaluated in terms of ion exchange capacity, electric resistance, elongation at break and water uptake.

• Toxicological Research
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• v.21 no.3
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• pp.241-247
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• 2005

HM10760 is a recombinant human erythropoietin that has beer developed as a drug for anemia. In this study, antigenic potential of HM10760 was examined by active systemic anaphylaxis in guinea pigs and passive cutaneous anaphylaxis in a guinea pig-guinea pig system. HM10760 was subcutaneously administered at 0, 2, and $20{\mu}g/kg$ and also as a suspension with adjuvant ($20{\mu}g/kg$ + FCA). Ovalbumin as a suspension with adjuvant was administered to induce positive control responses. In the active systemic anaphylaxis test, no symptoms except rubbing or licking nose and urination that were considered as physiological phenomena were observed at $0{\mu}g/kg$. Four of 5 animals at $2{\mu}g/kg$ and all the 5 animals at $20{\mu}g/kg$ showed cyanosis and lying on side. All animals in the adjuvant mixture group showed relatively mild symptoms such as rubbing or licking nose, urination, and evacuation. In the passive cutaneous anaphylaxis test, 0/5, 3/5, and 5/5 serum samples from the animals immunized with 0, 2, and $20{\mu}g/kg$, respectively, showed positive reactions against HM10760. All 5 sera collected from the animals immunized with an adjuvant mixture contained HM10760-specific antibodies. These results suggest HM10760 have antigenicity in guinea pigs.

• Annals of Geriatric Medicine and Research
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• v.20 no.3
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• pp.114-117
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• 2016

A research project, the "Construction of Frailty Cohort for Elderly and Intervention Study," funded by the Ministry of Health and Welfare, has been ongoing since December 2015. The Korean Frailty and Aging Cohort Study (KFACS) aims to identify risk factors for adverse outcomes associated with frailty in community-dwelling older adults, as well as means of prevention. KFACS is a multicenter, longitudinal study, with the baseline survey being conducted in 2016-2017. The sample (n=3,000) consists of those aged 70-84 years, stratified by age and gender, recruited from urban and rural regions nationwide. An in-person interview and health examination are performed every 2 years. This project is also conducting many intervention studies. Project interventions focus on nutrition and exercise. The nutritional intervention study compares the effects of 1.2 g/kg versus 1.5 g/kg daily protein intake on sarcopenia and frailty in older Koreans. The exercise trial examines the effectiveness of an information and communication technology-based program in preventing or reducing frailty.

• Korean Journal of Materials Research
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• v.31 no.9
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• pp.502-510
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• 2021

Hierarchically porous carbon materials with high nitrogen functionalities are extensively studied as high-performance supercapacitor electrode materials. In this study, nitrogen-doped porous carbon textile (N-PCT) with hierarchical pore structures is prepared as an electrode material for supercapacitors from a waste cotton T-shirt (WCT). Porous carbon textile (PCT) is first prepared from WCT by two-step heat treatment of stabilization and carbonization. The PCT is then nitrogen-doped with urea at various concentrations. The obtained N-PCT is found to have multi-modal pore structures with a high specific surface area of 1,299 m² g^-1 and large total pore volume of 1.01 cm³ g^-1. The N-PCT-based electrode shows excellent electrochemical performance in a 3-electrode system, such as a specific capacitance of 235 F g^-1 at 1 A g^-1, excellent cycling stability of 100 % at 5 A g^-1 after 1,000 cycles, and a power density of 2,500 W kg^-1 at an energy density of 3.593 Wh kg^-1. Thus, the prepared N-PCT can be used as an electrode material for supercapacitors.

• Journal of Environmental Science International
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• v.28 no.6
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• pp.561-570
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• 2019

A zeolitic material (Z-Y2) was synthesized from Coal Fly Ash (CFA) using a fusion/hydrothermal method under low-alkali condition (NaOH/CFA = 0.6). The adsorption performance of the prepared zeolite was evaluated by monitoring its removal efficiencies for Sr and Cs ions, which are well-known as significant radionuclides in liquid radioactive waste. The XRD (X-ray diffraction) patterns of the synthesized Z-Y2 indicated that a Na-A type zeolite was formed from raw coal fly ash. The SEM (scanning electron microscope) images also showed that a cubic crystal structure of size $1{\sim}3{\mu}m$ was formed on its surface. In the adsorption kinetic analysis, the adsorption of Sr and Cs ions on Z-Y2 fitted the pseudo-second-order kinetic model well, instead of the pseudo-first-order kinetic model. The second-order kinetic rate constant ($k_2$) was determined to be $0.0614g/mmol{\cdot}min$ for Sr and $1.8172g/mmol{\cdot}min$ for Cs. The adsorption equilibria of Sr and Cs ions on Z-Y2 were fitted successfully by Langmuir model. The maximum adsorption capacity ($q_m$) of Sr and Cs was calculated as 1.6846 mmol/g and 1.2055 mmol/g, respectively. The maximum desorption capacity ($q_{dm}$) of the Na ions estimated via the Langmuir desorption model was 2.4196 mmol/g for Sr and 2.1870 mmol/g for Cs. The molar ratio of the desorption/adsorption capacity ($q_{dm}/q_m$) was determined to be 1.44 for Na/Sr and 1.81 for Na/Cs, indicating that the amounts of desorbed Na ions and adsorbed Sr and Cs ions did not yield an equimolar ratio when using Z-Y2.

• Journal of Korean Society of Forest Science
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• v.100 no.4
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• pp.698-707
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• 2011

Over the past 10 years, South Korea has implemented various plantation projects including the Pine Restoration Project in Tujiin Nars and the desertification prevention forestation in Lun soum. This study has evaluated the implementation feasibility on the small-scale A/R CDM projects in Mongolia through which carbon emission credits can be secured. Characteristics, pros and cons, economic feasibility, and project execution feasibility were compared among three possible sites, Khyalganat, Tujiin Nars, and Lun soum. Among the three evaluated sites, Tujiin Nars has the better condition in tree growth, economic feasibility, and the applicability of experience than the other two sites. A/R CDM project in Mongolia, which has a great environmental benefit of combating desertification, is expected to have some effectiveness such as lowering costs from credit benefit, sustainable management by villagers, contribution to communities, investor's contribution to society and achievement of green image, and strengthening forestry cooperation between Korea and Mongolia.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.20 no.3
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• pp.23-30
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• 2010

Compression techniques can be applied to large-scale fingerprint systems to store or transmit fingerprint data efficiently. In this paper, we investigate the effects of FBI WSQ fingerprint image compression on the performance of a fingerprint verification system using multiple linear regressions. We propose a maximum compression using fingerprint image quality score. Based on the experiments, we can confirm that the proposed approach can compress the fingerprint images up to 3 times more than the fixed compression ratio without significant degradation of the verification accuracy.

• Biomolecules & Therapeutics
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• v.29 no.4
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• pp.419-426
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• 2021

In this study, we aimed to investigate the effects of 8 weeks of treatment with a combination of evogliptin and leucine, a branched-chain amino acid, in mice with high-fat diet (HFD)-induced diabetes. Treatment with evogliptin alone or in combination with leucine reduced the body weight of the mice, compared to the case for those from the HFD control group. Long-term treatment with evogliptin alone or in combination with leucine resulted in a significant reduction in glucose intolerance; however, leucine alone did not affect postprandial glucose control, compared to the case for the mice from the HFD control group. Furthermore, the combination of evogliptin and leucine prevented HFD-induced insulin resistance, which was associated with improved homeostasis model assessment for insulin resistance, accompanied by markedly reduced liver fat deposition, hepatic triglyceride content, and plasma alanine aminotransferase levels. The combination of evogliptin and leucine increased the gene expression levels of hepatic peroxisome proliferator-activated receptor alpha, whereas those of the sterol regulatory element-binding protein 1 and stearoyl-CoA desaturase 1 were not altered, compared to the case in the HFD-fed mice (p<0.05). Thus, our results suggest that the combination of evogliptin and leucine may be beneficial for treating patients with type 2 diabetes and hepatic steatosis; however, further studies are needed to delineate the molecular mechanisms underlying the action of this combination.